CHAPTER XXXIII
FORMS, COMPOSITIONS, CHARACTERISTICS,
ZODIACAL CLASSIFICATION, AND
PLACES OF ORIGIN
AMBER
- Hardness: 2-2.5.
- Lustre: Resinous.
- Chemical Composition: Carbon 78.96. Hydrogen 10.51. Oxygen 10.52.
- Specific Gravity: 1.10-1.13.
- Properties: Becomes highly electric by friction. When submitted to heat, organic compounds escape and leave a black residue.
- In the Zodiac: Amber is under the heavenly Taurus.
- Where found: Chiefly on the Baltic coast. On the Danish coast. Parts of Asia, etc.
BERYL
EMERALD—AQUAMARINE
- Crystalline System: Hexagonal.
- Hardness: 7.5-8.
- Lustre: Vitreous or Resinous. Transparent to translucent.
- Refraction: Weakly double.
- Chemical Composition: Silicate of Aluminium and Beryllium.
- Chemical Symbol: Be3 Al_{2 (SiO_{3)C.
- Specific Gravity: 2.63-2.75.
- Dichroism: Distinct.
- Properties: Exhibits frictional electricity. The emerald clouds before the blowpipe flame without fusing but under intensified heat the edges curve. With Borax the stone melts into a pale green bead. It resists acids but is affected by microcosmic salt. The stone is so fragile when taken out of the mine that friction crumbles it.
- In the Zodiac: All varieties of Beryls are under the Heavenly Taurus.
- Where found: Generally all over the world. Chiefly in Ekaterinburg, Brazil, India, United States, Australia.
CHRYSOBERYL
ALEXANDRITE—ORIENTAL CHRYSOLITE—CYMOPHANE OR CHRYSOBERYL—CATSEYE
- Crystalline System: Orthorhombic.
- Hardness: 8.5.
- Lustre: Vitreous. Transparent to translucent.
- Refraction: Double.
- Chemical Composition: Alumina 80.2. Glucina 19.8.
- Chemical Symbol: BeAl2O4.
- Specific Gravity: 3.7-3.86.
- Dichroism: Strong in Alexandrite. Distinct in Chrysoberyl.
- Properties: Crystals exhibit remarkable twinning at times. Chrysoberyl is highly electric and when submitted to frictional agitation holds electricity for a long time. Not affected by acids. Under the blowpipe it is unaltered and infusible, but it fuses tardily with borax or microcosmic salt. The Alexandrite variety which, as Professor J. G. Dana says, bears the same relation to ordinary Chrysoberyl as Emerald to Beryl, displays curious changes of colour from leafy green to raspberry red in real and artificial lights.
- In the Zodiac: Chrysoberyl is under the Heavenly Pisces; Alexandrite is under the Heavenly Aquarius.
- Where found: Ceylon, Brazil, Russia, Ireland, Australia, etc.
CORUNDUM
SAPPHIRE, RUBY, ORIENTAL AMETHYST, ORIENTAL EMERALD, ETC.
- Crystalline System: Rhombohedral.
- Hardness: 9.
- Lustre: Transparent to translucent.
- Refraction: Moderately double.
- Chemical Composition: Aluminium 53-53.2. Oxygen 46.8.
- Chemical Symbol: Al2O3.
- Specific Gravity: 3.90-4.16.
- Dichroism: Strong.
- Properties: Submitted to friction exhibits electrical properties which withdraw very slowly. Acids do not affect Corundum, but under the blowpipe in borax or microcosmic salt it gradually melts to a transparent globule. Radium influences the colour strongly, so much indeed as to impart it in achromatic specimens. The stone is variously affected by heat. Treated by Sir William Crooks by exposure to high tension electric currents in a similar way to the diamond the ruby phosphoresced with an intense red light, and the sapphire with an intense blue. Dr. T. Coke Squance of Sunderland, well-known in connection with radio-therapeutical research, has succeeded in transforming a faint pink sapphire into a fine ruby. During the process of transformation the lustre of the stone was so intensified that it nearly assumed the brilliancy of a diamond. Dr. Squance observed that both radium and X-rays cause a diamond to glow with a green light. “Besides the diamond,” he says, "a mineral called Kunzite glows with a lovely red hue. I submitted a sapphire to the Radium rays for a long period and it turned to a glorious red. In fact, it had become a ruby. I have similarly transformed other stones, a faint green sapphire, for instance, turning into an oriental emerald." Sir William Crooks noted the sage-green colour of the diamond under Radium, but found that the colour could easily be removed by mechanical means.
- In the Zodiac: Blue and green sapphires are under the Heavenly Aquarius; white are under the Heavenly Pisces; yellow or Oriental Topaz and Rubies are under the Heavenly Leo. Oriental Amethyst is under the Heavenly Sagittarius.
- Where found: Ceylon, China, Burma, Russia, East Indies, United States of America, Australia (chiefly Queensland), etc.
DIAMOND
DIAMOND—BOART
- Crystalline System: Isometric.
- Forms: Octahedron, dodecahedron. Crystals frequently twinned.
- Hardness: 10. Scratches every other stone.
- Lustre: Adamantine. Transparent and when dark, translucent.
- Refraction: Single.
- Chemical Composition: Pure Carbon.
- Chemical Symbol: C.
- Specific Gravity: 3.50-3.55.
- Properties: Exhibits positive electricity when rubbed, but is itself a non-conductor of electricity. When intensely heated it burns, yielding Carbonic Anhydride. When heated so as to exclude chemical combination it dilates and forms into a black concretion. It displays phosphorescence under Radium, when submitted to strong sunlight and, when put in a vacuum tube, to a high tension electric current. Dr. G. F. Herbert Smith found that "some diamonds fluoresce in sunlight, turning milky, and a few emit light when rubbed." Dr. Kunz proved that diamonds phosphoresce when exposed to the rays of Radium, Polonium, or Actinium, even when glass is interposed. These phenomena formed special object of experiment with the late Sir William Crooks, who showed that exposed to high tension electric currents in greatly rarified atmosphere, the diamond phosphoresced with an intense green light. Prismatic colours are radiated by this gem.
- In the Zodiac: The Diamond is under the Heavenly Aries, Leo and Libra.
- Where found: India, Borneo, Brazil, South Africa, Siberia, Australia, United States of America.
GARNET
ALMANDINE, PYROPE, HESSONITE, (GARNET HYACINTH), UVAROVITE
- Crystalline Form: Isometric.
- Hardness: 6.5-7.5.
- Lustre: Vitreous.
- Refraction: Single.
- Chemical Composition: Silica Alumina, Red Iron Oxide, Lime Magnesia, Manganese, Protoxide.
- Chemical Symbol: Dr. Smith has the following formulae:
- Hessonite Ca3 Al2(SiO4)3.
- Pyrope Mg3 Al2(SiO4)3.
- Almandine Fe3Al2(SiO4O)3.
- Andradite Ca3Fe2(SiO4O)3.
- Specific Gravity: 3.4-4.3.
- Properties: Exhibits positive electricity by friction. With the exception of Uvarovite, all varieties of Garnets fuse before the blowpipe flame. The stone generally does not contain water.
- In the Zodiac: The Almandine is under the Heavenly Sagittarius; the Pyrope, Aquarius; Hessonite, Virgo; Uvarovite, Aquarius.
- Where found: Generally all over the world.
OPAL
- Crystalline System: None.
- Form: Amorphous.
- Hardness: 5.5-6.5.
- Lustre: Waxy to subvitreous.
- Refraction: Single.
- Chemical Composition: Silica 91.32. Water 8.68.
- Chemical Symbol: SiO2, n=SiO2nH2O.
- Specific Gravity: 1.9-2.3.
- Properties: No electrical properties. Opal exhibits characteristic colour reflections known as Opalescence. It is susceptible to heat and weather changes, exhibiting greater brilliancy on hot than on cold days. The opal has never yet been successfully imitated, and certain peculiar properties yet remain to be investigated. Professor Frank Rutley F. G. S., emphasises the fact that "the nature of the Silica (Hydrous Silica) is not yet definitely determined." It is infusible before the blowpipe, but turns opaque.
- In the Zodiac: The Opal is under the Heavenly Leo, Libra and Aquarius. Leo favours red and fire opal; Libra, light translucent, pure colours, etc.; Aquarius, dark, black Opal, etc.
- Where found: Hungary, Honduras, Mexico, United States. The finest opal is now found in Australia, principally at Lightning Ridge, White Cliffs, Stuart’s Range, Charleville, etc. (Mr. Conrad H. Sayce gives (“Australasian,” March issue, 1920) an analysis of Stuart’s Range opal, bearing earth which contains about 35 per cent each of Alumina and Sulphur trioxide. He opines that this may account for the harmful effect it has on the men’s eyes and lungs.)
PEARL
- Hardness: 3.5-4.
- Lustre: Translucent.
- Chemical Composition: Carbonate of Lime and Organic matter.
- Specific Gravity: 2.65-2.89.
- Properties: Affected by acids. Benefitted by some skins, adversely affected by others. Destroyed by fire.
- Where found: Persian Gulf, Ceylon, Red Sea, South America, New Guinea, Thursday Island, Australia, etc.
- In the Zodiac: Pearls are under the Heavenly Cancer.
PERIDOT
CHRYSOLITE—OLIVINE
- Crystalline System: Orthorhombic.
- Hardness: 6-7.
- Lustre: Vitreous. Transparent to translucent.
- Refraction: Double.
- Chemical Composition: Silicate of Magnesium and Iron.
- Chemical Symbol: (Mg,Fe)2SiO4.
- Specific Gravity: 3.3-3.5.
- Dichroism: Distinct.
- Properties: Friction induces electricity in the stone which is infusible before the blowpipe, but is affected, whitening and forming with Borax, a yellow bead. Decomposes in Hydrochloric acid.
- In the Zodiac: The Peridot is under the Heavenly Pisces.
- Where found: United States, Ireland, Australia, (Queensland particularly), etc. A large number of Meteorites contain Peridots.
QUARTZ
ROCK CRYSTAL, AMETHYST, CAIRNGORM, CHRYSOPRASE, CATSEYE, PLASMA, JASPER, CARNELIAN, AGATE, ONYX, SARDONYX, MOSS AGATE
- Crystalline System: Rhombohedral.
- Hardness: 7.
- Lustre: Vitreous. Splendent to dull and resinous.
- Refraction: Double.
- Chemical Composition: Silicon 46.67. Oxygen 53.33.
- Chemical Symbol: SiO2.
- Specific Gravity: 2.5-2.8. In pure crystals 2.65.
- Dichroism: Distinct.
- Properties: Generates positive electricity by friction. It is infusible under the blowpipe, but effervesces with Carbonate of Soda. Although it resists the common acids it may be dissolved in Hydrofluoric.
- In the Zodiac: Rock Crystal is under the Heavenly Pisces; Amethyst is under the Heavenly Aries; Cairngorm under the Heavenly Scorpio; Chrysoprase under the Heavenly Cancer; Catseye under the Heavenly Capricorn; Plasma under the Heavenly Virgo; Jasper under the Heavenly Virgo; Bloodstone under the Heavenly Leo; Camelian under the Heavenly Leo; Agate under the Heavenly Scorpio; Onyx under the Heavenly Capricorn; Sardonyx under the Heavenly Leo; Moss Agate under the Heavenly Taurus.
- Where found: Distributed plentifully about the world. Rock Amethyst is found in the United States, Brazil, India, Ceylon, Ekaterinburg, Australia, etc. Mr. R. J. Dunn, late Victorian Geologist, discovered large quantities of Rose Quartz in South Africa. It is also found in the United States, Russia, Australia and other places. Catseyes are found in Ceylon and India. Cairngorm is found in Scotland, United States, Australia, etc. Chrysoprase is found in the United States and other places.
- Crystalline System: Isometric.
- Hardness: 8-8½.
- Lustre: Vitreous.
- Refraction: Single.
- Chemical Composition: Alumina 72. Magnesia 28.
- Chemical Symbol: MgAl2O4.
- Specific Gravity: 3.5-4.0.
- Dichroism: None.
- Properties: Does not display electricity when submitted to friction or heat, but under heat the red spinel changes to brown. On cooling it becomes green, after which it is nearly colourless; then it resumes its pristine hue. Spinel crystals also change into Hydrotalcite, a soft pearl-like stone of similar chemical composition. Infusible alone under the blowpipe but yields slowly with Borax. It is soluble in concentrated Sulphuric Acid.
- In the Zodiac: Spinel, Balas, Almandine, Ruby and Sapphirine are under the Heavenly Virgo. The Chloro-Spinel and the Pleonaste are under the Heavenly Capricorn.
- Where found: United States, Canada, Burma, Siam, Ceylon, Australia, etc. It is discovered in granular limestone, in gneiss and rocks of volcanic origin.
SPODUMENE
KUNZITE—HIDDENITE
- Crystalline Form: Monoclinic.
- Hardness: 6.5-7.
- Lustre: Pearly. Translucent to subtranslucent.
- Refraction: Double.
- Chemical Composition: Silicate of Aluminium and Lithium.
- Chemical Symbol: Li A1 (Si O3)2.
- Specific Gravity: 3.5-3.20.
- Dichroism: Strong.
- Properties: Electrical. Unaffected by acids. Under the blowpipe flame expands and melts into a clear or opaque glass, indicating lithia by colouring the flame red. Kunzite exhibits phosphorescence under Radium.
- In the Zodiac: Spodumene and Kunzite are under the Heavenly Libra. Hiddenite may be under the zodiacal Taurus.
- Where found: United States of America, Madagascar, Brazil, Sweden, etc.
TOPAZ
- Crystalline Form: Orthorhombic.
- Hardness: 8.
- Lustre: Vitreous. Transparent to translucent.
- Refraction: Slightly double.
- Chemical Composition: Silicate of Aluminium.
- Chemical Symbol: [A1(F,OH)]2SiO4. (Penfold and Minor.)
- Specific Gravity: 3.4-3.65.
- Dichroism: Distinct.
- Properties: Becomes strongly electric by friction, heat and pressure. Infusible alone before the blowpipe flame, but with Borax melts into a bead. Changes colour when heated.
- In the Zodiac: The Topaz is under the Heavenly Scorpio.
- Where found: Brazil, Ceylon, Mexico, United States, Australia, etc.
TOURMALINE
- Crystalline Form: Rhombohedral.
- Hardness: 7-7.5.
- Lustre: Vitreous.
- Refraction: Double.
- Chemical Composition: Varied, but all varieties include silicate of alumina, boracic acid, iron, magnesia, lime and soda, sometimes lithia in small quantity, with fluorine and trace of phosphoric acid.
- Chemical Symbol: Professors Penford and Foote refer all varieties of Tourmaline to (H6Na6Mg3Al2)3(Al,Fe)6(B,OH)4Si8O38,
- Specific Gravity: 2.39-3.3.
- Dichroism: Strong.
- Properties: Becomes charged by heat and friction with positive and negative electricity. Before the blowpipe flame the darker varieties fuse easily but the lighter more tardily.
- In the Zodiac: The Tourmaline family is under the Heavenly Gemini.
- Where found: Brazil, Russia, California and other parts of the United States, Ceylon, Australia, etc.
TURQUOISE
- Crystalline Form: None.
- Hardness: 6.
- Lustre: Waxy.
- Chemical Composition: Dr. Smith gives the composition as a complex phosphate of Aluminium, iron and copper.
- Chemical Symbol: Dr. Smith gives Penfold’s formula as [Al(OH)2Fe(OH)2,Cu(OH)Cu(OH),H]3PO4,
approaching nearly to H5Al2PO8.
- Specific Gravity: 2.6-2.8.
- Properties: Infusible before the blowpipe flame, but changes its colour to brown. Dissolves in Hydrochloric acid. Is affected by acids, oils, the health of the wearer, etc.
- In the Zodiac: Turquoise is under the zodiacal Sagittarius.
- Where found: Chiefly in Persia where the best specimens are found. Also found in Mexico, Russia, United States, Australia, etc.
ZIRCON
ZIRCON, JARGOON, HYACINTH OR JACINTH
- Crystalline System: Tetragonal.
- Hardness: 7.5.
- Lustre: Adamantine. Transparent to opaque.
- Refraction: Strongly double.
- Chemical Composition: Silica 33. Zirconia 67.
- Chemical Symbol: ZR SiO4.
- Specific Gravity: 4.6-4.86.
- Properties: Exhibits frictional electricity. The Zircon is infusible before the blowpipe flame but coloured specimens lose their colours. With borax Zircon melts under the blowpipe into a transparent bead. Heated with lime the Zircon is transformed into a straw-coloured stone which so closely resembles the yellow diamond that it is sold to travellers by some unscrupulous Eastern dealers as the more costly gem. Scientists have not yet been able to explain the constitution and distinct characters of the Zircon satisfactorily. Professor Sir A. H. Church has made a technical study of the zircon for over half a century, and is universally accepted as its most authoritative student. In his researches he found that in certain varieties of zircon the green and yellow stones, ground on copper wheel with diamond dust, exhibit a sparkling orange light, and the intermediate golden types radiate orange tints in the flame of a Bunsen burner. Students are seeking for the unknown element which, blended with zirconium, defies detection. The Zircon is very little affected by acids, except sulphuric acid after very long steeping. It is also peculiar that when first heated the stone exhibits strong phosphorescence, but as its colour leaves it, its specific gravity is magnified and it will not again phosphoresce when reheated after cooling.
- In the Zodiac: All varieties of Zircon are under Heavenly Virgo.
- Where found: In almost every part of the world.