Albite

Img: Tourmaline with Albite (Cleavlandite)

Alternative names

Although Albite is often called White Feldspar and Plagioclase, it is actually an isomorphous solid solution series of the Plagioclase Feldspar group. Whilst it is technically correct to call it either of those names, it is a broad name for it as Albite is at one end of the spectrum of plagioclase feldspars, containing sodium and no calcium and Anorthite is at the other end of the plagioclase feldspar spectrum, containing calcium and no sodium.

Cleavelandite, Pericline and Peristerite are also varieties of Albite.

Identification

As one of the most common members of the feldspar family, in its thin sections, Albite can look like it has little speckles of dirt or confetti sprinkled in it and can usually be found in white to grey but can also be bluish, greenish, reddish or even colourless.

There are 2 variants of albite, referred to as “low Albite” and “high Albite” (also known as Analbite) and whilst they are both triclinic, they differ in volume of their unit cell (which is slightly larger for Analbite) and can be formed by heating Low Albite to higher than 750 degrees celsius, meaning that it is most often found in meteor impact craters such as in Winslow, Coconino, Co. Arizona. You would be forgiven for mistaking this stone with Rainbow Moonstone (White labradorite) by initial appearance as they are both from the feldspar family and thus are incredibly similar to view when white. Moonstone is a type of Albite and so you would not be incorrect by calling moonstone "albite".

If it were to be heated even higher (to above 1050 degrees celsius), it changes to a monoclinic crystal known as “monalbite”.

Albite has a melting temperature of 1,100-1,200 degrees celsius and often, potassium can replace the sodium in albite up to 10% to be then called “anorthoclase”

images

img1: Albite; img2: Tourmaline & albite with Quartz; img 3: Albite; img 4: Albite with Actinolite inclusions; img5: Albite with Chlorite inclusions

Countries it can be found

Albite was first found in Finnbo, Falun, Dalarna, Sweden in 1815 but has since been found in multiple places in Canada and the Scandiavian Peninsula. As it is the feldspars to crystallize from molten rock, it can often be found with other rare minerals. It can also be found in Germany, Essex County New York, Austria, USA, Brazil and Kenya and its polymorphs have been found in Lake Kumdikol Diamond Deposit (Kumdykolite) and Sixinghou meteorite (Linguinite).

Eytmology:

Albite was named in 1915 but Johan Gottlieb Gahn and Jons Jacob Berzelius, taking its name from the Latin word “Albus” meaning “white”, alluding to its usual color.

Metaphysical Properties

This stone is said to be useful for:

- eliminating problems in the live, kidneys, spleen, pancreas and stomach

- transmitting the energy of the Sun and Moon.

- combating depression, chronic fatigue and stress

- aiding in calming those prone to irritation and aggression

- absorbing negative energies and filling the user with calm and patience.

It has also been said to be good luck when travelling and its presence in the home is said to help protect the home and bring harmony.

Scientific Properties

Formula: NA(AlSi3O8)

Mohs hardness: 6-6.5

Polymorph of: Kumdykolite & Lingunite

Occurrence: Usually forms at low temperatures and is common in pegmatites, granite and igneous rocks as well as marbles and various metamorphic rocks.

Fracture: Irregular/Unevan, Conchoidal

Cleavage: imperfect to perfect depending on specimen

Crystallography: Triclinic, Twinned, platy crystals

refractive index: 1.527-1.544

birefringence: 0.008-0.011

Dispersion: 0.012

luminescence: Usually none, may be whitish in Low wave, lime-green in X-rays

Luminescence type: Fluorescent, UV-long, X-ray colours

Pleochroism: None

Optics: α = 1.527; β = 1.531; γ = 1.538. Biaxial (+); 2V = 77°

Optic Sign: Biaxial +

Lustre: Vitreous to pearly

Specific Gravity:

Transparency: Transparent, Translucent

Tenacity: Brittle

Not sure what these words mean? Click here to see a post explaining them!

Can it be faceted?

Clean gems are typically in the 1-3 carat range and can be faceted although up to 50 carats in Catseye has been known.

How to care for it

As this is not a capricious stone there is no special care needed for it. To remove dirt and dust, simply rinse it under cool water and dry it with a soft cloth.

Sources

Wikipedia, Mindat, eratarot.com, gemsociety.org

Images: Google