Fuchsite

Fuchsite (Verdite) is a variety of muscovite, a green color rock of chrome mica with chemical composition aluminium silicate. The green emerald color is due the high percentage of chromium and it is a good simulant for emerald.
It is generally formed either in fibrous or massive form in pegmatite. The best known fuchsite comes from South Africa. Due to the low hardness of fuchsite 2.5 - 4, it is advised not to use it in day to day life as it can get scratch.
Fuchsite is very familiar with ruby. Ruby - Zoisite is a stone where by ruby is naturally occurred within fuchsite better now known as ruby in fuchsite. This stone is extensively worn as beads and can be used in daily basis.

Properties

Chemical Composition: 

Aluminium Silicate - Al₃(SiO₄)₃

Classification / Type: 

It is a rock of chrome green mica, also known as verdite when found in South Africa.

Colors / Varieties: 

Green

Crystal System / Forms: 

Monoclinic System / Fibrous, massive, flaky.

Hardness: 

2.5 - 4

Specific Gravity: 

2.80 - 3.00

Cleavage / Fracture: 

None / Conchoidal.

Optic Character: 

A.G.G.

Lustre: 

Vitreous to waxy.

Refractive Index / Birefringence: 

1.580 - 1.590 / 0.010

Pleochroism: 

Not Common.

Dispersion: 

-

Magnification: 

Crystalline inclusions of chlorite, flaky structure.

U.V. Fluorescence: 

Variable.

Spectrum: 

Chromium Spectrum (similar to emerald)

Cause of Color: 

Chromium

Treatment (Enhancement): 

-

Specific Tests & Remarks: 

-

Synthesis: 

-

Simulants (with key separation tests): 

Emerald (S.G., structure, inclusions), Jade (R.I., S.G., spectrum, inclusions, structure)

Geological Occurrence: 

Pegmatites

Sources: 

South Africa, Australia, U.S.A.

Cuts & Uses: 

Facetted, cabochon, etc.