This obsidian locality is one of the most well-known glass sources in the Southwest. The perlite here was mined historically and "Apache Tears" are sold by individuals owning land on the source. “Apache Tears” look non-transparent and black in the reflecting light; in the penetrating light they look transparent and lightly brownish.

The name "Apache tear" comes from a legend of the Apache tribe: about 75 Apaches and the US Cavalry fought on Picketpost mountain overlooking what is now Superior in the 1870s. Facing defeat, the outnumbered Apache warriors rode their horses off the mountain to their deaths rather than be killed. The wives and families of the warriors cried when they heard of the tragedy; their tears turned into stone upon hitting the ground.

At Superior, the obsidian nodules are eroding from perlite. Nodules are most common on the east slope of Picketpost Mountain within a rhyolite/perlite regolith and in small washes eroding north into Queen Creek. Nodule densities are up to 20 per m², but the nodule sizes are generally less than 5 cm in diameter. Some are 'on sale' that approach 8 cm. The density and nodule size recorded are probably skewed by the heavy collection that has occurred here in recent years.