Star Gems

By: Hoffman, Douglas L.

Price: $35.00

Quantity: 1 available


B&W Illustrations; This is a trade sized booklet with cardstock covers and a stapled spine. The book and its contents are in clean, bright condition. There are a couple of small spots of discoloration to the covers by the spine. The text pages are clean and bright. "In gemology, chatoyancy or chatoyance or cat's eye effect, is an optical reflectance effect seen in certain gemstones. Coined from the French "œil de chat", meaning "cat's eye", chatoyancy arises either from the fibrous structure of a material, as in tiger's eye quartz, or from fibrous inclusions or cavities within the stone, as in cat's eye chrysoberyl. The precipitates that cause chatoyance in chrysoberyl are the mineral rutile, composed mostly of titanium dioxide. Examined samples have yielded no evidence of tubes or fibres. The rutile precipitates all align perpendicularly with respect to cat's eye effect. It is reasoned that the lattice parameter of the rutile matches only one of the three orthorhombic crystal axes of the chrysoberyl, resulting in preferred alignment along that direction. " (from Wikipedia)

Title: Star Gems

Author Name: Hoffman, Douglas L.

Categories: Arts And Crafts,

Edition: 1st Edition; 1st Printing

Publisher: Aurora Lapidary Books: 1967

Binding: Stapled wraps

Book Condition: Very Good+

Seller ID: A38317

Keywords: Arts & Crafts Douglas L. Hoffman Star Gems Lapidary Chatoyancy Cat's Eye Gemology Arts and Crafts,