Quartz is, after feldspar, the most abundant mineral on the earth crust. There are two big families within the quartz minerals: the macro-crystalline, mostly transparent varieties and the micro-crystalline (or crypto-crystalline), which are translucent or opaque. The opaque range includes agate and jasper.
Rutilated quartz is a transparent rock crystal with rutile inclusions. Black Rutilated quartz is a pure quartz which contains a unique pattern of needle-like black tourmaline.
Gemstone, pure quartz or rock crystal, natural, rough, faceted long chips, 10x15-10x35 mm, top-drilled - Mohs' hardness 7.0 - one strand is +/- 38 cm and has +/- 48 beads
Gemstone, warm silver grey quartz or silver quartz, natural, 6x6mm, round beads – frosted – Mohs' hardness 7.0 - one unit is +/- 19 cm and has +/- 32 beads
Gemstone, pure quartz or rock crystal, India, natural, 8x10 mm, puffy oval beads - faceted, hand-cut – B-grade, Mohs' hardness 7.0 - one unit is +/- 35 cm and has +/- 34 beads