 | | Journal (issue) | | Number 2 TABLE OF CONTENTS FEATURE ARTICLES 62 Sri Lanka: The Gem Island Peter C. Zwnan The Identification...a n y fine gemstones found on the island o f Sri Lanka, the subject of Peter Zwaan's article i n this...this issue. This fine 9.57-ct cabochon from Sri Lanka is pictured here against a 19th century lithograph...not of the publishers. SRI LANKA: THE GEM ISLAND By Peter C. Zwaan Sri Lanka, formerly Ceylon, remains...mined by primitive methods. In many instances, the Sri Lankan origin of the gemstone can be determined by |  | | Journal (issue) | | Colombian Emeralds Ron Ringsmd The Elahera Gem Field in Central Sri Lanka Mahinda Gunawardene and Mahinda...COLOMBIAN EMERALDS By Ron Ringsrud The Muzo emerald district, i n Boyacd, Colombia, contains several mines...used to describe the best. Yet Colombia's Muzo district actually encompasses several mines, of which two...emeralds mined in Colombia come from the Muzo district, and the Coscuez mine has grown to become the...Colombian emeralds among the local Indians as far north as Mexico and as far south as Peru and northern |  | | Journal (issue) | | emerald, Colombia; (11) 8.31-ct pink sapphire, Sri Lanka; (12) 5.79-ct pink spinel, Pamir Mountains, USSR;...From top to bottom, left to right, are a 42.33-ct pyrope-spessartine garnet, a 28.41-ct tanzanite, a 22...other continents as well. In Africa, the Kitwe district in Zambia has become a major source of good, strongly... comm., 1990). CHRYSOBERYL The gem fields of Sri Lanka continued to be the major source of fine chrysoberyl...1980s) significant amounts continued to be found in Sri Lanlza and Burma, with the Cambodian deposits largely |  | | Book | | nucleation initiation of crystal growth. nucleus the central portion of an atom, positively charged and containing...crystals of magmatic (igneous) origin such as olivine, pyrope and diopside in diamond. Pegmatite minerals such...formation cannot occur in a host from another; pyrope which is formed at great depths and high pressures...pyrochlore) and zircon crystals are common in Sri Lanka gemstones. The more important syngenetic mineral...mica in andalusite, chrysoberyl, kornerupine and Sri Lanka sapphire • calcite in Burmese ruby and spinel; | | | Book | | nucleation initiation of crystal growth. nucleus the central portion of an atom, positively charged and containing...crystals of magmatic (igneous) origin such as olivine, pyrope and diopside in diamond. Pegmatite minerals such...formation cannot occur in a host from another; pyrope which is formed at great depths and high pressures...pyrochlore) and zircon crystals are common in Sri Lanka gemstones. The more important syngenetic mineral...mica in andalusite, chrysoberyl, kornerupine and Sri Lanka sapphire • calcite in Burmese ruby and spinel; |  | | Journal (issue) | | spinel samples. The marbles were analyzed by the Central Analytical Laboratory and the Polevskaia Laboratory...that has been called the "Uralian ruby-bearing province" (Kissin, 1990a). To date, approximately 100-150...approximately 50,000); Chelyabinslz-about 120 lzm to the north-is the largest city (population: about 1.2 million)...(structural)features: (I) Western Uralian fold belt; (11) Central Uraliun Uplift; (111) Tagilo-Magi~itogorosliii...Light-colored calcite marble in Kootchinskoye quarry's north wall is representative of material i n which ruby |
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