EOSC 118 Lecture 22: Other Gemstones 1
Document Summary
Learning objectives: describe why some gemstones are more commonly carved or cut "en cabochon" rather than faceted, describe the difference between nephrite and jadeite. Summarize the composition, properties, and famous localities of turquoise. Summarize the composition, properties, and famous localities of lapis lazuli. Summarize the composition, properties, and famous localities of ammolite: describe how pearl, amber and coral are formed and how they differ from most other gemstones. Cabochon and carved opaque to translucent gems many of the gemstones that are fashioned into cabochons or carved do not readily form transparent crystals appropriate for faceting. However, they typically show vibrant colours or interesting textures that are valued. Organic gems gems also originate from organic material and play an important role in the gem and jewellery industry. Many of these gems have the same qualities and characteristics that mineral-based gemstones have and deserve their acknowledgment as genuine gemstones. The three most common organic gems are pearl, amber, and coral.
