. . . "1915-05-15"^^ . . . . "2002-05-17"^^ . . . "John Sinkankas"@en . "John Sinkankas (1915\u20132002) was an honored Navy officer and aviator, noted gemologist, gem carver and gem faceter, author of many books and articles on minerals and gemstones, and a bookseller and bibliographer of rare books."@en . . "gemologist, micromounter, bookseller, bibliographer, US Navy officer."@en . . . . "John Sinkankas (1915\u20132002) was an honored Navy officer and aviator, noted gemologist, gem carver and gem faceter, author of many books and articles on minerals and gemstones, and a bookseller and bibliographer of rare books."@en . "John Sinkankas"@en . "American"@en . "Paterson, New Jersey"@en . . . . .