Meaning

noun a yellow quartz

noun a mineral (fluosilicate of aluminum) that occurs in crystals of various colors and is used as a gemstone

noun a light brown the color of topaz

originVarious theories. Hobson-Jobson mentions as possibilities a corruption of Persian (from Turkish) top-chi, "gunner", or a connection with topee, from the hats they wore.

Etymology from Wiktionary, CC BY-SA 3.0