_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 SiO_{4}. _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. CHAPTER XXXIV GEMS IN HERALDRY, MAGICAL SQUARES OF ABRA MELIN THE MAGE, CHARUBEL’S GEM INFLUENCES, GEMS OF COUNTRIES GEMS IN HERALDRY “_Sweet mercy is nobility’s true badge._” “TITUS ANDRONICUS.” Without doubt the science of Heraldry was evolved from ancient astrological philosophy.