Quartz is the second most abundant mineral in the Earth's continental crust, after feldspar. It is a 7 on the Mohs scale of hardness. In fact, the word “Quartz” means “hard” from Slavic.
There are many different varieties of quartz, several of which are semiprecious gemstones. Especially in Europe and the Middle East, varieties of quartz have been since antiquity the most commonly used minerals in the making of jewelry and hardstone carvings.
Pure quartz, traditionally called rock crystal (sometimes called clear quartz), is colorless and transparent (clear) or translucent, and has often been used for hardstone carvings, such as the Lothair Crystal.
Rose quartz is a type of quartz which exhibits a pale pink to rose red hue. The color is usually considered as due to trace amounts of titanium, iron, or manganese. Some rose quartz contains microscopic rutile needles which produces an asterism in transmitted light (rutilated quartz.)
In crystal form (rarely found) it is called pink quartz and its color is thought to be caused by trace amounts of phosphate or aluminium.
Smoky quartz is a gray, translucent version of quartz. It ranges in clarity from almost complete transparency to a brownish-gray crystal that is almost opaque. Some can also be black.
Milk quartz or milky quartz may be the most common variety of crystalline quartz and can be found almost anywhere. The white color may be caused by minute fluid inclusions of gas, liquid, or both, trapped during the crystal formation.
Mystic quartz is a patented name for cut quartz which has been coated with a ultra-thin layer of metallic titanium on the pavilion faces.
This coating generates interference patterns in light much like oil spread on water does, leading to a rainbow of colors in the stone.
Here is a photo of silver earrings with pink quartz and white CZ:
Here is a photo of silver earrings with created blue quartz and white CZ:
Check out more jewelry with quartz.