Mineralpedia Details for Albite

Formula

NaAlSi₃O₈ 

Crystal System

Triclinic 

Crystal Habit

Blocky, Striated, Granular 

Cleavage

Perfect, Good, None 

Luster

Vitreous (Glassy) 

Color

white, gray, greenish gray, bluish green, gray 

Streak

white 

Class

Triclinic - Pinacoidal 

Fracture

Uneven 

Hardness

7 

WebMineral

View Albite 

Mindat

View Albite 

These are some of the larger Albite crystals you'll see of Albite. The crystals are a pearly white color and are tabular to 3.5cm across! There is very little to no damage, although there is some natural etching on some of the faces. There are also large 3cm Muscovite crystals.

White crystals with blue schiller effect in places. 

Cabinet specimen and crystal aggregate with many faces displaying blue iridescent reflections. According to Sinkankas, peristite should reflect a variety of hues and a hue of blue only is usually reserved for moonstone. Moonstone however should have a schiller effect. This specimen does not. To be consistent with locality information on Mindat and the old label, this specimen will be termed peristerite. As is typical of plagioclase feldspar, polysynthetic or albite twinning can be see along some faces as striations.

Special Info

Antique Specimen

This is a variety of Albite called oligoclase, which should contain at least 70% Na, so very close to end member Albite. Tilting this specimen back and forth you will see tiny reflections of oriented hematite crystals withing the oligoclase. This property is gives the name "sunstone" to some oligoclase.

This is a variety of Albite, known as pericline, taking its name from the Greek word, periklinis, or inclined on all sides (Mindat).  Pericline is the variety of Albite with a glazed porcelain-like luster and milky white color. Pericline is elongated and twinned along the b-axis and thus have long tapering faces along the prism form.

Lustrous white elongated crystals to 1.4cm, var. pericline.

Special Info

Gem Quality

Light yellow gemmy labradorite. This material has weathered out of basalts. This labradorite has no schiller effect since there there are probably no exsolved layering which causes the labradorescence (schiller).

Andesine is a variety of Albite composed of 50-70% Albite and 30-50% Anorthite. It is of a late a fine red gem but can be yellow and green, obviously this specimen is not a gem.  Associated with this Andesite are black crystal plates of ilmenite.

Pericline crystal group with white glossy crystals to 2cm. The crystals are elongated by twinning on the b-axis with long inclined faces along the prism.

This is one of the most famous localities for labradorite and locally called "spectrolite". The specimen is a large coarse crystalline mass with tightly packed crystals to over 1cm. Many of the crystals show excellent play of colors or schiller effect caused by exsolved lamellae. Labradorite is not a variety but a defined mineral species within the plagioclase series at least according to Mindat. I never understood this since Bytwonite is a variety within the same series and not granted species status. 

Colorless to light greyish white, glassy oligoclase with Diopsode and garnet.

Cleavelandite is white to colorless and platy variety of Albite found in pegmatites. Cleavelandite is usually found along the fringes or outer zones of the pegmatites.

White platy crystals, the variety of Albite called cleavelandite. 

Special Info

Gem Quality

Gemmy yellow Albite, supposedly "sunstone".

Special Info

Illustrated in London's book "Pegmatites"

This specimen from the border zone represents an example of wall-rock interaction with the pegmatite solution as it was injected into the country rock. The white portion is the pegmatite and is composed of Albite, Muscovite, Beryl. The black portion is the wall rock, which through metasomatism, was altered to Schorl tourmaline.

The specimen is illustrated in "Pegmatites" on page 123 Fig. 7-12d.