America, near Greensboro in North Carolina, in the districts around Lake Superior, especially the north-west.
It is usually step-cut and mounted a jour. A massive variety, called Prime d'Amethyst, is cut into cups and vases.
4.
Rose Quartz is a pink or pale red variety, usually showing a vitreous
lustre and small conchoidal fracture; usually not crystallised, and but
rarely transparent. Its colour is due to traces of titanic oxide, and
is prone to fade on exposure, though it may to some degree be restored
by moistening the specimen. When of fine colour it may be cut and sold
as " Bohemian Euby "; more often it is cut into plaques with a curved
upper surface. It is rather a rare variety. Localities where it is
found are Babenstein and Konigswerth in Bavaria, Ekaterinburg in the
Urals, and Beinn Doireann in Scotland. It is distinguished from glass
imitations by its hardness and double refraction.
5.
Yellow Quartz, or Citrine, is a variety that is often used to imitate
yellow Topaz, which it much resembles in colour, hence it is often
called " Occidental Topaz " or " Spanish Topaz." Like Rose Quartz, it
is one of the rarer varieties. Scottish localities are Loch Avon and
Goatfell; in France at Bourg d'Oisans ; mostly found in Brazil and
Uruguay (often with Amethyst), and is thence sent to Oberstein to be
cut. In the Sierra Morena in Spain a variety which assumes a good
yellow colour on heating is found ; this is cut and sold as " Spanish
Topaz." It is disÂtinguished from Topaz when in the rough state by its
want of cleavage and by being softer. When cut it may be disÂtinguished
by its lower specific gravity and very weak dichroism.
