73.—Topaz.
Occurs in crystals; glassy lustre; brittle; scratches rock-crystal; not acted upon by ordinary heat or acids; gravity 3.5.
Value.—A gem; the most esteemed are the rose-red and white.
Localities.—Found in granite. Trumbull, Willimantic and Middletown, Conn.; Crowder’s Mountain, N. C.; Thomas’s Mountains, Utah.