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Quartz Gem Colors

Quartz is found worldwide and is one of the most durable and attractive minerals on earth. Made up of silicon dioxide, quartz stones range from transparent to translucent. The stone is quite hard so it can be cut, carved or polished into various shapes. Some quartz contains small crystals known as chalcedony. Pure quartz stones are clear or milky in color; colored quartz stones have some other mineral mixed in them, which gives them their color.

Amethyst
- Quartz stones that combine with iron form amethyst. The colors can range from deep purple, violet, and lavender. When an amethyst is treated with heat, it turns yellow and forms citrine. The deeper the purple color of the quartz stone, the more expensive it becomes.
Rose Quartz
- One of the most rare and desirable colors of quartz, the pink color of rose quartz comes from iron and titanium within the stone. Rose quartz is a cloudy opaque gemstone that gemstone cutters usually form into cabochons for use in jewelry.
Smoky Quartz
- Smoky quartz colors range from gray to brown or black. Smoky quartz often contains embedded crystals, which form lines of inclusion in the stone, called rutilated quartz. Smoky quartz attains its color from the element aluminum.
Citrine
- Citrine quartz ranges in color from pale smoky yellow to deep orange. Citrine derives its color from iron or aluminum deposits in the stone. True citrine is not heat treated and is very rare.
Aventurine
- Aventurine quartz appears green, golden brown or reddish brown depending upon the presence of green mica or hematite. Aventurine is usually heat treated to brighten its color. An opaque stone, gemstone cutters often form it into cabochons or beads for use in the jewelry industry.
Cat's Eye
- Cat's eye quartz, also known as tiger's eye, forms because of embedded lines of crocidolite or iron oxide within the quartz. Usually dark brown with golden inclusions, the polished stones show a striped pattern that seems to move as the stone is turned. Some forms of cat's eye show a variety of colors ranging from white to yellow to blue.
Carnelian
- A translucent quartz stone that ranges in color from pale to near reddish orange, carnelian obtains its color from iron deposits within the structure of the stone. Often heat treated to improve its color; carnelian should never appear banded or striated.
Chrysoprase
- An apple green chalcedony, chrysoprase derives its color from nickel deposits within the structure of the stone. Its clarity varies from nearly transparent to opaque. Colors range from medium to olive green and it is often mistaken for jade.

Gemology