Precious Stones and Gems ... Third edition

Front matter

PRECIOUS STONES AND GEMS Howlett & Son, Old Style Printers, io, frith street, soho, London, w. PRECIOUS STONES AND GEMS, Their History and distinguishing Characteristics rv EDWIN W. STREETER, F.R.G.S., " Gold Medallist of the Royal Order of Frederic ; " " Holder of a Gold Medal from H.M. the King of the Belgians ; " GOLD" its Legal Regulations and Standards, &>c, &>c. JHlustratrt. The Great "Table" Diamond, 242! carats. THIRD EDITION, LONDON GEORGE BELL & SONS. YORK STKEK'I COVENT GARDEN r882 " I hold every man a debtor to his profession, from the which as men of course doe seeke to receive countenance and profit, so ought they of duty to endevour themselves by way of amends, to be a helpe anJ ornament thereunto. This is performed in some degree by the honest and liberall practice of a profession, when men shall carry a respect not to descend into any course that is corrupt and unworthy thereof, and preserve themselves free from the abules wherewith the fame profession is noted to bee infected ; but more is this performed isa man bee able to vifite and strengthen the roots and foundations of the fame itself, thereby not only gracing it in reputation and dignity, but also amplifying it in perfection and lubstance. " LORD BACON. List of Illustrations.

Part I

The "Stewart" Diamond (Frontispiece) Great " Table" Diamond (on Title-page) " Shah " Diamond (Preface, p. xiii.) Proper Sizes of Brilliants face page 38 Proper Sizes of Rose Diamonds ... „ 40 Kimberley Mine, No. i. , 7-8 Kimberley Mine, No. 2. „ 78 The "Dudley" Diamond „ 83 The "Twin" Diamond 83 Brazilian Diamond „ 93. Cape Diamond (shewing Garnet) , 93 Diamond Sand 93 Diamond Matrix 104 Cape Yellow Diamond (Octahedron) ... „ 101 Indian Diamond „ 104 Blue Diamonds „ 117 Diamond Boring Drills , 121 tT

Part II

Rubies „ 17 Sapphires „ 17 Emeralds (Crystal) „ 17 Turquoise ... „ 48 Topaz (in Crystal) „ 48 Opal ,, 48 Alexandrite „ 62 Rubies and Sapphires (in Sand) ... ,, 6z Cat's Eye „ 62

Part III

Pearls (White and Coloured) „ Contents PA0E5 To the Reader ... IX Preface to the Second Edition ... ... XV

Part I. Section

I. — Precious Stones in general.— Chapter I. ...Definition of the terms "Gem " or " Precious Stone-' 17 — 18 Chapter II Where Precious Stones are found ... ... ... ... ... 19 — 21 Chapter III. ...Precious Stones and their uses in bygone times ... .. ... 22 — 28 Chapter IV. ...The Working of Precious Stones 29 — 48 Chapter V Precious Stones as Objects of Commerce ... ... ... ... 49 — 52

Section II

— Chapter I The Diamond 53 — 70 Chapter II South-African Diamonds... 71 — 86 Chapter III. ...Australian Diamonds ... 87 — 92 Chapter IV. ...Brazilian Diamonds ... 93 — 103 Chapter V Indian Diamonds ... ... 104 — 113 Chapter VI Colored Diamonds ... 114 — PAGES Chapter VII.. ..Bort and Carbonado ... 120 — 124 Chapter VIII. Celebrated Diamonds ... 125—139 Chapter IX. ...Rough Diamonds ... ... 140 — 141

Part II. Section III

— Colored Stones 1—2 Chapter I Corundum ... .... ... 3 — ro Chapter II. ...Ruby n — 16 Chapter III. ...Sapphire 17—22 Chapter IV. ...Emerald ... ... ... 23—30 Chapter V. ...Spinel and Balas Rubies ... . 31 — 34 Chapter VI. ...Opal ... ... ... ... 35 — 39 Chapter VII. Cat's Eye ... ... ... 40 — 43 Chapter VIII. Turquoise ... ... ... 44 — 48 Chapter IX. Star Stones or Asteria ... 49 — 51

Section IV

— Semi-Precious Stones.— 52 Chapter I. ...Amber ... ... ... ... 53 — 55 Chapter II. ... Amethyst ... ... ... 56 — 58 Chapter III. Agate 59 — 61 Chapter IV. ...Alexandritf 62 — 63 Chapter V. ... Aquamarine 64 — 66 Chapter VI. ...Bloodstone 67 — 68 Chapter VII. Carnelian, or Red Chalcedony 69 — 72 Chapter VIII. Chrysolite (Chrysoberyl) ... 73 — 74 Chapter IX. ...Chrysoprase 75 — 77 Chapter X. ...Garnet, Carbuncle, Jacinth and Cinnamon Stone ... ... 78 — 82 Chapter XI. ...Jasper... 83 — 86 Chapter XII Labrador 87—88 Chapter XIII. Lapis-Lazuli ... 89 — 91 Chapter XIV. Malachite ' ... 92 — 94 Chapter XV. Selenite or Moonstone ... 95 — 97 Chapter XVI. Onyx 98 — 100 Chapter XVII. Peridot 101— 102 Chapter XVIII. Quartz Cat's Eye ... ... PAGES Chapter XIX. ...Rock Crystal 104 — 107 Chapter XX Topaz 108 — no Chapter XXI. ...Tourmaline in — 113 Chapter XXII. Zircon, Jargoon, or Hyacinth 114 — 117 Chapter XXIII. ..Coral 118— 122

Part III. Section IV

..Pearls 1—4 Chapter I Sea Pearls ... ... ... 5—17 Chapter II Colored Pearls ... ... 18 — 22 Chapter III. ...River Pearls 23 — 26 Remarks on the term Carat ... ... ... 27 Indexes 29 — TO THE READER ANY pages have been written on the history of PRECIOUS STONES. Authorities on authorities, from remote antiquity to this our day, have been cited as to their value, their uses, their beauties, and their properties, and still one might venture to say that there are fewer judges of the genuineness and real value of Precious Stones than there are treatises to guide people to such knowledge. Would it be altogether unwarrantable to express a grave doubt whether even in the trade there are very many skilled in detecting the real measure of difference between one stone and another, either by that most essential test, the specific gravity, or by minor tests of rarity and quality ?

Be this as it may, I have arrived at the deliberate conviction, as a merchant and dealer long versed in the purchase and sale of gems, that some practical and popular guide to those who have an interest in ascertaining and testing the genuineness and value of Precious Stones, is in demand and would be useful. A gem should be a real possession, capable of affording pleasure to the wearer and the spectator, and, with fair X usage, retaining an intrinsic and marketable value, undi minished by lapse of time. I have sometimes seen in wear gems so scratched that their lustre has been seriously impaired, and a suspicion excited in the minds of wearers, friends, and dealers, that there was a defect in the hardness of the stones, and consequently in their genuineness. It would be worth while to point out that a small sum expended in re-polishing such stones would restore their original lustre, revive the pleasure derived from the possession of them, and prevent them from being sold as paste or imitation jewellery.

A lady had bequeathed to her some family jewels, consisting of a Sapphire and Diamond suite. As they had passed probate several times, there was no doubt in the mind of the legatee of the genuineness of the Sapphires. On being applied to in relation to their value, I had to pronounce them to be only paste. Had they been genuine they would have realized from £30,000 to £40,000. One often sees the Spinel and the Baias — the one a lively poppy-red, and the other a violet-rose — usurping the dignity of the true Ruby, and yet the pure Ruby of ten carats is worth from £3,800 to £4,800, and the other stones, called by the same name, would be dear at one twentieth the sum. The Chrysolite of the Ancients, though highlyesteemed by them, has not retained its popular character. It is by us termed the Oriental Topaz, and is a Corundum formed of alumina, colored golden-yellow by oxide of iron.

The ordinary Topaz of commerce, composed of silica and alumina, with hydrofluoric acid (hydric-fluoride), commonly of a pale orange, toning down to a straw color, is of com paratively little value. It can, however, be made almost any color by burning. It is quite pardonable, and of small consequence, that the characteristics of such gems should be comparatively unknown ; but there are Precious Stones about which there should be no doubt in the minds either of the purchaser or the merchant, viz., the Diamond, Ruby Emerald, Sapphire, Opal, Cat's-eye, Alexandrite, and Pearls. A lady refuses to wear a gown composed of inferior material intended to represent silk, because its colour texture, and draping indicate, to every experienced eye, the substitution of the false for the real ; but she seems to ignore the fact that the color, brilliancy, and texture of a true gem, are as distinguishable from those of the false or mere imitation, as the cotton from the silk.

We pre sume to believe that the gown, which in a few nights wear loses its worth altogether, is of less consequence as to the genuineness of its material than gems which should be heirlooms of value, not much deteriorated by the lapse of years. In the division of family jewels much injustice is often done by persons incompetent to form a correct opinion of their relative values. A study of this hand-book may serve to demonstrate the difficulty of an accurate discrimination. In all cases it would be wise to submit the jewels to a practised judge, both for valuation and probate. It is not right to leave the decision to some house agent or mutual friend. Some study and attention will be required to attain a knowledge of the properties and appearance of gems, but the subject is by no means unattractive, and may be turned to good account.

The study of Pearls, especially, is not so intricate as is generally believed. Isa little attention be paid to the ascertained mode of their construction, which is in fine concentric layers, this will readily supply the key to detect spurious fabrications. The peculiarities of these products of organised nature are not very difficult to understand ; but if the specimens are large, and of supposed great value, it would not be undesirable to obtain the opinion of a skilled judge in such matters, especially in relation to colored Pearls. With objects, such as those referred to above, I am publishing the present volume, the outcome of more than thirty years' experience, and of the united knowledge of many men of science, and of my contemporaries in trade. I hope that it may be of some service to us as merchants, to our customers, and to the public in general.

It must be borne in mind that this book is not in tended to be a scientific treatise, but a practical work for those who, whether in the trade or among the public at large, desire to obtain some knowledge of the general characteristics of Precious Stones and Gems. In conclusion, I trust that the Goldsmiths' Company as fathers of the trade, will ere long throw open their fine suite of rooms in Foster Lane. To them we must look for aids to the more general appreciation of fine art jewelry, by affording favorable opportunities for exhi bitions and prizes, similar to those offered by the Turners' Company, together with gratuitous lectures, and the free use of their reading room to members of the trade. This would give an impetus to study to those engaged in jewelry-work, and enable the public to obtain a more accurate knowledge of, and a deeper interest in, a subject which has hitherto remained the property of an exclusive few.

The legacies bequeathed to the Goldsmith's Company by the famous jewellers of the 15th, 16th, and 17th cen turies, which have since increased in value to an extent almost inconceivable, without doubt were intended for some such purposes as those to which I have referred. I am in an especial manner indebted for the subject matter which forms the basis of this work, to the works of Professor Kluge, translated by Mrs. Brewer ; and also to Major F. B. Beaumont, M.P., Mr. James A. Forster, and others. These contributors are authorities in the depart ments of science in which they have conceded me their invaluable assistance. I hope shortly to be in a position to publish a history of all the known large Diamonds of over thirty carats weight. Difficulties of no ordinary nature have been met with in compiling this record.

Conflicting statements have been carefully analysed, and the truth or fallacy of the same, verified or exposed by reference to original documents. EDWIN W. STREETER, F.R.G.S. Bond Street, London, 1882. The ''Shah'' Diamond, weight 86 carats.

Preface

TO THE THIRD EDITION. rTyHE complete exhaustion of the previous edition of this ■"• work has created an urgent need for a further issue, inasmuch as the favorable notice it has received at home aud abroad has stimulated the demand for it. The gracious acceptance of a copy by Her Majesty the Queen, and the distinguished honor of a special Gold Medal accorded me by His Majesty the King of the Belgians and also by the King of Wurtemburg, who has been graciously pleased to command the " Gold Medal and Blue Ribbon of the Royal Order of Frederics to be transmitted to me, as a mark of his august approval of the Book, have prompted an early publication of a third edition. In this, as in the second edition, further original matter has been introduced, more especially on the subject of Pearls, in regard to which new information has been acquired only by persevering and distant research, carried on at no small cost of time and labour.

I have been stimulated thereto by a desire to do everything in my power to render the book as worthy as possible of the popularity and distinguished patronage which have been so liberally accorded it. EDWIN W. STREETER, F.R.G.S Bond Street, London. 1882.

Chapter I

definition of the term gem, or precious stone. GEM, termed on account of its great worth a " Precious Stone," is a mineral of exceptional hardness, of beautiful color, or absolutely colorless. Usually it is transparent, or translucent ; of extreme rarity, and of principal value in the manufacture of jewelry. Generally, minerals possessing these characteristics are divided into two classes, (i) Jewels or Gems proper, technically, but incorrectly, called "Oriental Stones." These are pre-eminent for beauty and value. (2) " Semi-Precious Stones," whose color, brilliancy, or density are inferior to the former. The first class comprehends those rarer minerals which are distinguished by their color ; brilliant and sparkling as though some beautiful object or natural effect of light and soft color, had been instantaneously caught and per manently fixed.

The finest specimens of this class are characterised also by transparency and lustre united to extreme density and capability of polish. A Definition of the term Gem or Precious Stone. 18 Precious Stones of the second class are endowed with the same qualities only in a minor degree. They are less rare, and are found over a wider range, and sometimes in much greater abundance. This classification is however, artificial, many specimens out of each set being apportioned to the higher or the lower class, because of some special property peculiar to themselves. As we might conclude from the above remark, even the money value affords not an infallible test of the class to which a specimen gem may ordinarily belong. Acci dental circumstances of form, peculiarity of color, or some whim of fashion may cause a " Semi-Precious Stone " to be preferred to one of the first class, and vice versa.

By the science of Jewelry is commonly implied a knowledge of the properties and peculiarities of Precious Stones, viz., in what their excellence consists ; their physi cal and chemical properties ; the relation they bear to other minerals ; their shape and structure ; their defects and impurities ; and therefore this science must include a com petent and experimental knowledge of Geometry, Physics, and Chemistry. It will be obvious that many chemical and physical instruments will be required throughout the study of this science, such as the blowpipe, spirit lamp, a goniometer for measuring angles, scales of various construction for testing the specific gravity, and files and lenses for testing their hardness and optical properties.

Chapter II

where precious stones are found. HE habitat, or native home of Precious Stones, will be specially indicated in the description of each individual gem, or the class to which it belongs ; we shall, therefore, content ourselves with a very few general remarks upon the subject, Precious Stones, unlike exceptional vegetation, which is confined to definite geographical limits and climate, occur abundantly and in about equal perfection in all latitudes, the only needful condition being that the moun tain ranges in which they are sought must possess well ascertained geological formations ;' so that the saying holds good, that in no zone does every class of rocky elevation constitute the habitat of precious minerals. The Diamonds of Golconda are hardly, if at all, to be distinguished when polished, from those found in the Ural mountains, or in Brazil.

The Emerald of Peru is much the same as that which is found in Upper Egypt or Catharineburg. The Beryl of Siberia has proved no un equal rival to that of Brazil, and the Amethysts of the Palatinate equal those found in Ceylon, or the favored spots of South America. It is not indeed, the geographical position which Where Precious Stones arc found. 20 determines the difference between the relative value of the sites, but the generally acknowledged fact that in India, Brazil, and Ceylon, larger gems and a greater abundance of them have been discovered than elsewhere. The Ancients were wont to ascribe this pre-eminence to evaporation from the earth where Precious Stones are found — an evaporation obviously more intense in tropical countries. It was accounted for on the supposition that the sunburnt tropics were more favorable to the blossoms of the inorganic world, than the dark skies of the north.

But although Precious Stones are not limited to any defined geographical area, their distribution is in a measure circumscribed, inasmuch as they are not met with in all mountain ranges, nor in all formations of mountains. The most valuable are found in such ranges as are considered the oldest in the world, composed of granite, gneis, por phyry, and mica-slate. Sometimes they occur imbedded in the mass of the rock ; at other times, protruding, as it were, on the surface. When they are thus found, in the very rocks where they were originally formed, they are said to be in their primeval bed. Many, however, are found far from their primal home, in a derivative or secondary bed, in diluvial or alluvial soils, and in the gravels and sands of river-beds. This last mode of occurrence is the most frequent for the finer Precious Stones.

Far removed from their native home by the force of heavy rains and rushing torrents, they, have been loosened and carried onwards, rounded by friction against the debris with which they have been accompanied in their course. It is by their hardness and density that they are preserved, and many even retain traces of their original crystalline form. In Ceylon, India, Brazil, Australia, California, the Ural, Siberia and South Africa — from which countries the Where Precious Stones are found. 21 great majority of our Precious Stones are obtained — they more usually occur in these derivative beds ; and it is interesting to notice how various kinds of Precious Stones are found in the same locality, forming as it were a noble society of Gems, still more illustrious by their association with gold and platinum.

Chapter III

precious stones and their uses in bygone times. RECIOUS Stones were valued and preserved by the Ancients thousands of years ago. In India, where the most costly were chiefly found, this was especially the case. Other Eastern lands, on the contrary, possessed Precious Stones, and handed them down from generation to generation without knowing anything of their worth or nature, valuing them simply for their transparency, their dazzling beauty, their hardness, their crystalline forms, all of which excited their wonder, and induced them to preserve them as amulets, or to use them as personal ornaments. We know that in the time of Solomon, the love of grace and luxury induced the rich to desire the possession of Precious Stones, and even to seek for them in foreign lands. In Egypt, in ancient times, many semi-precious stones and scarabæan gems were worked ; and we learn from the Septuagint, and from Philo, that the robes of the High Priest were set with Precious Stones.

The names the Hebrews gave these stones indicate that they derived their knowledge of them from the Egyptians, who un doubtedly, in common with other ancient races, knew little of what we understand by Mineralogy. As regards India, Strabo and Pliny tell us that gold and Precious Stones were used for personal adornment, and that drinking cups were formed of precious metals set with Emeralds, Beryls, and Rubies. From the East the Phœnicians, in their universal traffic, exported costly stones as well as ivory, with Syrian purple and other stuffs, which were known as early as the Homeric period. The songs of Homer contain references to valuable bright stuffs and stones which served for ornament, without mentioning their special names or qualities. For instance — " the witch puts on her costly robe and brilliant earrings," but their nature is not defined.

Eurymachus gives to Penelope an exquisitely worked neck lace of gold, ornamented with light amber, bright as the sun. Eurydamas gives magnificent earrings, such as must have been worn by high-born ladies and princesses in Homeric times. The precious Onyx and the Sapphire are mentioned by Job, with the Coral, Pearls, Rubies, and Topaz of Ethiopia ; and the place in which some were found appears to have been known by that patriarch of Uz : " He putteth forth His hand upon the rock : He cutteth out rivers among the rocks, and His eye seeth every precious thing." Six or seven hundred years B.C. the Greeks knew of many Precious Stones, and the rulers in Greece and neighbouring lands wore ornamental and signet rings made with cut stones. The famous ring of Polycrates (died B.C. 522) was doubtless as valuable to him for its costly stones and workmanship, as for any hidden virtue which it is said to have possessed.

Herodotus, and some later Greek authors, mention Theodorus of Samos, the first engraver of stones, as the maker of that ring. In the beginning of the 5th century, B.C., we find among the Greeks, a didactic History of Precious Stones ; which indicates that their knowledge of them was not superficial. Onomacritus, a Priest and Founder of Hellenic mysteries, 500 years B.C., treated of Precious Stones and their mysterious power, Commencing with the bright trans parent crystal, he says, " Whoso goes into the Temple with this in his hand may be quite sure of having his prayer granted ; as the gods cannot withstand its power." Further, he states, " that when this stone is laid upon dry wood, so that the sun's rays may shine upon it, there will soon be seen smoke, then fire, then a bright flame." This flame was known among the Ancients as holy fire, and they believed that no sacrifice was so acceptable to the gods as when offered through its agency.

In like manner, Onomacritus sang the praises and supernatural power of the Agate, the Topaz, the spring green Jasper, Amber, Chrysolite, Coral and Opal. The superstitions attached to these and other stones were not confined to the Ancients. Even in this enlightened age, the Empress Eugenie of France, would not wear a precious Opal because it was said to bring ill luck to the wearer. Queen Victoria, on the contrary, having no such super stition, has presented each of her daughters, on their marriage, with a parure of Opals and Diamonds. After the early Greek period the knowledge of Precious Stones advanced. Herodotus must have had accurate acquaintance with many of them. He mentions, besides the Emerald in Polycrates' ring, signet rings, such as that of Darius ; and speaks of the so-called Emerald column in the Temple of Hercules at Tyre, which at night gave out a wonderful light.

Plato mentions the Sard, Jasper and Emerald. The Adamant— our modern Diamond — Amber and Loadstone were not unknown to him ; and he shows some knowledge of the origin of both common and Precious Stones, and of their natural hexagonal, octagonal and prismatic forms. It is certain that Aristotle had a knowledge of a still larger number of Precious Stones, and that he was acquainted with some of their special properties. His scholar, Theophrastus, has left us a small work on this subject. Diodorus mentions the Topaz found in the Serpent Island of the Arabian Sea ; this is probably what we now call Chrysolite. Dionysius Periegetes mentions the clear and brilliant Diamond, the beautiful Astrios that glitters like a star, the Lychnis, with the color of fire, the blue Beryl, the dull Jasper, the pure bluish or greenish Topaz, and the lovely Amethyst with its soft, purple sheen.

In the time of Alexander the Great, and still more so in the time of the luxurious Diadocheus, there was a great increase in the use of Precious Stones as articles of luxury. They were not only used for signet rings, but also in ornamenting many articles of use and luxury, particularly drinking vessels and candelabra. After the Romans became possessed of the treasures of Asia and Africa, they probably gained a much fuller knowledge of Precious Stones. Pliny must have been better informed than his predecessors as to the places where gems were found. From him also we gain most of our knowledge of the views of the Ancients as to Precious Stones. During this period the luxury of Rome in respect to Precious Stones was enormous. The Emperors adorned their robes with jewels of immense value. Paulina, the wife of Caligula, covered her dress entirely with Emeralds and Pearls of untold worth.

Pliny says "we drink out of a mass of gems, and our drinking vessels are formed of Emeralds." A little later they began to set their sacred pictures in frames adorned with gems. Constantine entered Rome in a chariot of gold, adorned with Precious Stones which sent forth brilliant rays of light, and in his time the royal crown was first set about with Precious Stones. This custom of ornamenting crowns with gems has been con tinued to the present day. Passing on to the Christian Era ; among writers upon Precious Stones, Isidorus, Bishop of Seville, in the year 630 A.D., takes a prominent place. He classified gems according to their color. The number of properties attributed to Precious Stones at that time is wonderful. They were said to have the power of conferring health, beauty, riches, honor, good fortune and influence.

Men and women carried them about their persons, and called them Amulets. They were thought also to have some connection with the planets and seasons. A special gem was worn for each month : thus — In January The Hyacinth. „ February „ Amethyst. „ March „ Jasper. „ April „ Sapphire. „ May „ Agate. „ June „ Emerald. .. July „ Onyx. „ August „ Carnelian. „ September „ Chrysolite. „ October „ Beryl. „ November „ Topaz. „ December „ Ruby. The Twelve Apostles, also, were represented by gems, called Apostle-stones, viz : — 1. — The' hard and solid Jasper, representing the rock of the Church, was the emblem of Peter. 2. — The bright-blue Sapphire was emblematic of the heavenly faith oi Andrew. 3. — The Emerald, of the pure and gentle John. 4. — The white Chalcedony, of the loving James. 5. — The friendly Sardonyx, oi Philip. 6. — The red Carnelian, of the martyr Bartholomew. 7. — The Chrysolite, pure as sunlight, of Matthias. 8. — The indefinite Beryl, of the doubting Thomas. 9. — The Topaz, ofthe delicate James the younger.

IO. — The Chrysoprase, of the serene and trustful Thaddeus. 1 1. — The Amethyst, of Matthew the Apostle. 12. — The pink Hyacinth, of the sweet-tempered Simeon of Cana. In later times, an Alphabet was formed of Precious and Semi-precious Stones. TRANSPARENT. A. Amethyst. B. Beryl. C. Chrysoberyl. D. Diamond. E. Emerald. F. Felspar. G. Garnet. H. Hyacinth. I. Idocrase. K. Kyanite. L. Lynx-sapphire M. Milk-opal. N. Natrolite. O. Opal. P. Pyrope. Q. Quartz. R. Ruby. OPAQUE. Agate. Basalt. Cacholong. Diaspore. Egyptian Pebble Fire-stone. Granite. Heliotrope. Jasper. Krokidolite. Lapis-lazuli. Malachite. Nephrite. Onyx. Porphyry. Quartz-agate. Rose-quartz. TRANSPARENT. S. Sapphire. T. Topaz. U. Uranite. V. Vesuvianite. W. Water-sapphire X. Xanthite Z. Zircon. OPAQUE. Sardonyx. Turquoise. Ultra-marine (Lapis).

Verd-antique (Porphyry). Wood-opal. Xylotile. Zurlite. If, for instance, you wanted the word Alice represented in a ring, you would choose Amethyst, Lynx-sapphire, Idocrase, Chrysoberyl and Emerald ; or any other group of stones whose initial letters spell the name.

Chapter IV. The Working Of Precious Stones

f|HKH| HE qualities for which Precious Stones are jÆB^JK most prized, viz., lustre, transparency, re- IgllSpjii fraction, and dispersion of light, are to some l^fesE-asd extent visible even in their rough state ; but in order to enhance these advantages, and render them more attractive, the stones must be subjected to artistic cleaving, grinding, and polishing. The cleaving, grinding, and polishing appertain to the art of the lapidary, whose aim is so to manipulate the rough stone, as to produce regular, or symmetrical and smooth surfaces, called facets. The subsequent cutting of designs or mottoes in the polished stone belongs to the engraver. It does not appear that the Ancients understood the art of the lapidary so well, or, at any rate, valued it so highly as we do. They preferred weight to brilliancy, and size to effectiveness.

They would have been horrified to sacrifice eighty carats of a stone weighing 186 carats, merely to enhance its effectiveness as a gem. Accordingly, we see that they were generally content to rub down the angles, polish the surfaces, and retain the fanciful shapes each stone possessed when discovered. The clasp of the regal mantle of Charlemagne (in the French national collection), is found set with Diamonds with their natural planes of the octahedron only partially polished. In the year 1290 there was formed a guild of gem-polishers and cutters in Paris, and in 1373 the art of diamond-polishing was practised in Nurnberg ; their mode of procedure is, however, unknown to us. It was not till a subsequent date, that the famed " table-cutters " of Nurnberg formed themselves, in conjunction with the stone-engravers, into a regular guild.