Colored Stones 27 - Organics:Collectors Stones PDF
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Gemological Institute of America
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Summary
This document provides an overview of organic gem materials, including amber and coral. It discusses the properties and origins of amber, mentioning its preservation of insects and the sources from the Baltic Sea region and the Dominican Republic. It also mentions different coral types.
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Colored Stones 27 KEY CONCEPTS Many sources of organic gem materials are endangered and The most valuable red coral is an intense red that dealers call protected by environmental laws. oxblood. To be called amber, tree resin has to harden over time and be...
Colored Stones 27 KEY CONCEPTS Many sources of organic gem materials are endangered and The most valuable red coral is an intense red that dealers call protected by environmental laws. oxblood. To be called amber, tree resin has to harden over time and be Because Italy is the most important coral-marketing center, at least a million years old. many coral color terms are Italian. Amber is probably best known for its preserved insects and Nearly all trade in new elephant ivory has been illegal since other inclusions. the mid-1970s. The Baltic Sea region and the Dominican Republic are amber’s Jet was popular as mourning jewelry in the late Victorian era. principal sources. There are two basic types of gem coral: calcareous coral and conchiolin coral. Key Terms Sun spangles—Circular marks sometimes left in amber when treaters heat and oil it. 290
