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Red Carnelian Cab
HEXAGONAL

Carnelian

SiO2

Hardness
7
Refractive Index
1.54–1.55
Spec. Gravity
2.63–2.65
System
Hexagonal
Carnelian is the red, orange, or amber variety of Chalcedony. Though often a solid color, it may also be banded, in which case it would be jointly classified as both Agate and Carnelian. Carnelian is an ancient gemstone, having been used as gem material since antiquity. Although still used a gemstone today, its significance and value has been diminished since the ancient times.

About

Carnelian, being a Chalcedony gemstone, can sometimes have its classification borderline with other Chalcedony gemstones. Sard, which is the brownish to brownish-red translucent form of Chalcedony, can sometimes be a color that can fall under either category. The name Sard can also be used interchangeably with Carnelian, though it is accepted that Carnelian on the redder spectrum and Sard on the browner spectrum. Sard has more historical significance over practical usage, as it is not commonly used as gemstone today.

Carnelian differs from Jasper in that Jasper will always be opaque, whereas Carnelian is translucent. Carnelian may be nearly opaque but will still let light through when viewed from the edges. Jasper usually also exhibits multicolored patterns and splotches which are lacking in Carnelian. Though Carnelian is often a solid color, it may contain lighter and darker zones within a single stone, or cloudy areas.

Uses

Carnelian is a minor jewelry gemstone. It is cut and polished into cabochons, and used as beads for necklaces and bracelets. It is also carved into cameos which can be worn as pendants. Carnelian is occasionally used as an ornamental stone and carved into animal carvings or ornamental objects.

Varieties

✓ common  · ✗ uncommon

Treatments & Enhancements

Most Carnelian is naturally colored, though some lighter-toned stones may be heat treated to enhance color. Some Carnelian on the market is dyed white Chalcedony or lightly colored Agate.

Sources

Sources of Carnelian include India, Brazil, Uruguay, and the Unites States (New Jersey and Oregon).

Similar Gemstones

Fire Opal is usually a brighter color and more transparent than Carnelian, and is always softer. Amber may resemble Carnelian, but it is much softer.

Further Reading

Faceted

See all 7 faceted photos →

In the Rough