Apache tears

Common card · No. 416281

Apache tears are rounded pebbles of obsidian or "obsidianites" composed of black or dark-colored natural volcanic glass, usually of rhyolitic composition and bearing conchoidal fracture. Also known by the lithologic term marekanite, this variety of obsidian occurs as subrounded to subangular bodies up to about 2 in (51 mm) in diameter, often bearing indented surfaces. Internally the pebbles sometimes contain fine bands or microlites and though in reflected light they appear black and opaque, they may be translucent in transmitted light. Apache tears fall between 5 and 5.5 in hardness on the Mohs scale.

Read on Wikipedia · Image Simon Eugster --Simon 20:06, 14 April 2006 (UTC), CC BY-SA 3.0