quartz crystal points - teaching student set of 12 from Brazil These clean sharp rhombs of

These clean sharp rhombs of colorless calcite are from the Challenger Cave system near Monterrey

roughly 15 miles south of Fallon and just west of US Highway 95

inhibiting the formation of dacite

green and variously wild-colors of the calcite you see being sold at rock shows and shops use an artificial dye

forming porcelanite

quartz crystal points - teaching student set of 12 from Brazil These clean sharp rhombs ofQuartz is identified by its hardness, non metallic luster, translucency and faint horizontal striations on crystal faces. The striations may not appear on every face, and they range from faint to obvious, so a student will have to be observant. These are useful student specimens; each is transparent with a terminated end. Its interesting to see quartz points offered in 50 gram lots on the Internet. That sounds like a lot, but its just 1. 7 ounces, so