Amethyst quartz
Amethyst quartz , also known as banded amethyst or coarse amethyst and known under the trade name chevron amethyst , is a layer-like intergrowth of opaque to translucent, milk-white quartz and the purple quartz variety amethyst . The white quartz stripes can appear in a V-shape and are usually only clearly visible after the stone has been cut and polished.
Amethyst quartz is used exclusively as a gem and ornamental stone . In order to bring out the banding of the stone as appealingly as possible, only smooth cuts are used. Mostly these are spherical cuts or cabochons for chains, pendants and rings. Amethyst quartz is also drummed for simple hand flatterers ( baroque stones) . Due to its structure, however, amethyst quartz tends to break out of quartz spots.
There is a risk of confusion with striped fluorite , especially the purple-white "Blue John" fluorites from Derbyshire , England. However, fluorite has a Mohs hardness of 4 and, unlike amethyst quartz, can be scratched with a knife.
literature
- Walter Schumann: Precious stones and gemstones. All species and varieties in the world. 1600 unique pieces . 13th revised and expanded edition. BLV Verlags-GmbH., Munich et al. 2002, ISBN 3-405-16332-3 , p. 134 .
Individual evidence
- ↑ EPI - Institute for Gemstone Testing. Name search (entry of chevron amethyst required)
- ^ Precious stone etiquette by Prof. Leopold Rössler. Amethyst quartz