Superior obsidian

Superior obsidian, also called Picketpost Mountain, comes from northeastern Pinal County in central Arizona, in Tonto National Forest and nearby private land. It is one of the best-known glass sources in the Southwest, and its nodules, called marekanites, erode out of perlite. They are usually under 5 cm, though some reach 8 cm. The glass is aphyric and nearly transparent brown, a few pieces showing banding, with a thin whitish perlite rind. Shackley calls it an excellent knapping glass, second to none in the Southwest. It appears in Archaic through Preclassic Hohokam sites across central Arizona, where it was the preferred stone for the small serrated points called Snaketown Serrated at Snaketown and the Grewe site. Superior and Vulture glass must be separated chemically.

Marekanite nodules eroding from perlite on the east slope of Picketpost Mountain in a rhyolite and perlite regolith, and washing northward and west down the Queen Creek drainage. Nodule density up to 20 per m2, mostly under 5 cm; the density may be reduced by heavy modern collecting.