Glittering Stones » Semi Precious Stones » Chalcedony

Semi Precious Stone Chalcedony

Chalcedony is defined as a fibrous cryptocrystalline form of silica and composing a variety of mineral Quartz and moganite with a trigonal crystal structure. The chalcedony mineral has waxy luster and it may be semitransparent or translucent.

The various types of chalcedony:

Agate: Agate is the variety of chalcedony with unique multi colored angular banding pattern. It is also referred as "jasper", owing to its opaque nature. With brown back ground the stone shows phenomenal iridescence and resembles landscapes.

Aventurine: The aventurine is a light resisting translucent quartz crystal with mineral inclusions which makes the stone to shimmer. The green color of the crystal is attributed to hematite impurities.

Carnelian: The carnelian, also known as spelled carnelian is reddish brown in color and its diaphaneity varies from translucent to opaque. Intense brown color variety of carnelian is called as "sard".

Chrysoprase: The green variety of chalcedony is called as chrysoprase. The green color is imparted to the quartz stone by nickel oxide.

Heliotrope: The heliotrope is the unique type of chalcedony, which is green in color with red spots that resembles drops of blood. Since, the stone has red spots it is called as "blood stone", if the stone as yellow spots then it is called as "plasma".

Moss agate: The superficial appearance of the moss gate is attributed to green filament like inclusions. It has 3D effect, owing to its transparent background. It doesn't belong to typical agate family, since it lacks the distinct concentric banding property.

Uses: The semi precious stone is used in concrete repair and industrial process. It is also widely used in crystal healing, owing to its superficial nature. The stone can relieve vocal strain and it is highly connected to spirituality and wisdom.

Historical Facts of Chalcedony

Refractive Index: 1.530 - 1.539

Chemical Composition: SiO2

Hardness: 6 - 7

Density: 2.59 - 2.61

Crystal Group: Hexagonal

Crystal system: Trigonal

Luster: Waxy, Vitreous, Dull, Greasy, Silky

Other names: Chalcedon, Calcedonia, Calcédoine

Varieties: Agate, Carnelian, Chrysoprase, Heliotrope, Moss agate

Color: White, Gray, Grayish blue, Brown, Pale black, Green, Blue, Lavender

Ocurrence: Brazil, Afghanistan, U.SA. Germany, India, Uruguay, Austarlia, Egypt, Italy, Scotland, South Africa, Namibia, Madagascar

Gem Chalcedony Jewelry