John Sinkankas
John Sinkankas (May 15, 1915 – May 17, 2002) was a Navy officer and aviator, gemologist, gem carver and gem faceter, author of many books and articles on minerals and gemstones, and a bookseller and bibliographer of rare books. Provided by Wikipedia-
Gemstone & mineral data booka compilation of data recipes formulas and instructions for the mineralogist gemologist lapidary jeweler craftsman and collectorBookby Sinkankas, John
Published 1988