Tuesday, 29 November 2016

Andradite Gemstone

What is Andradite?

Andradite is a species of the garnet group. It was named after the Brazilian mineralogist José Bonifácio de Andrade e Silva (1763–1838). Andradite includes three varieties:
  1. Melanite: Black in color, referred to as "titanian andradite".
  2. Demantoid: Vivid green in color, one of the most valuable and rare stones in the gemological world.
  3. Topazolite: Yellow-green in color and sometimes of high enough quality to be cut into a faceted gemstone, it is rarer than demantoid.
It was first described in 1868 for an occurrence in Drammen, Buskerud, Norway.

Occurrence

Melanite
It occurs in skarns developed in contact metamorphosed impure limestones or calcic igneous rocks; in chlorite schists and serpentinites and in alkalic igneous rocks (typically titaniferous). Associated minerals include vesuvianite, chlorite, epidote, spinel, calcite, dolomite and magnetite. It is found in Italy, the Ural Mountains of Russia, Arizona and California and in Dnipropetrovsk Oblast in Ukraine. Like the other garnets, andradite crystallizes in the cubic space group, with unit-cell parameter of 12.051 Å at 100 K. The spin structure of andradite contains two mutually canted equivalent antiferromagnetic sublattices below the Néel temperature.
Demantoid
Topazolite

Andradite Healing Properties

The energies and healing powers of Andradite Garnet reflect the strength and protection of all garnets. Its physical healing power encourages the stimulation and regeneration of blood, the assimilation of vital minerals, and strengthens the immune system.
Emotionally, Andradite Garnet brings strength, stability and balance, promoting self-confidence and self-esteem. It is associated with the Base, Heart and Solar Plexus Chakras, opening up the mind to higher thinking and better relationships, and stimulating creativity, will and focus.
It is a powerful spiritual cleanser. Andradite Garnet ranges in colour energy from green to dark olive, deep yellow, and a glossy black. Melanite, the black variety is an excellent meditation aid with powerful grounding abilities.
A host of angels are associated with Andradite's colour energies and it honors two Goddesses. Garnet is the traditional birthstone of January, and Andradite is the natural birthstones of those born in the in the heart of spring (April 20-May 20) and the beginning of summer (June 21-July 21).
Garnet is the zodiac stone for those born under the sign Aquarius, and is an Enhancer Strengthener crystal. It has the properties of Wood and Water energies, and is a talisman of protection.

Physical Properties of Andradite

Chemical FormulaCa3Fe3+2Si3O12
ColourRed, Green, Yellow, Orange, Brown, Pink, Gray, Black, Multicoloured
Hardness6.5 - 7.5
Crystal SystemIsometric
Refractive Index1.888 - 1.889
SG3.8 - 3.9
TransparencyTransparent to opaque
Double RefractionNone
LusterAdamantine, submetallic
CleavageNone
Mineral ClassAndradite (Garnet)