Know what you're buying and selling: the feldspars

Shimmers
Originally uploaded by salyx

I have recently seen a lot of larvikite being sold as spectrolite. I thought I would jump in here and straighten things out.

First of all, we will start with labradorite.

Labradorite (calcium sodium aluminum silicate) is a stone that doesn't look special until you see what we like to call "the flash". The surface of the stone shows off an amazing array of colors (sometimes a full spectrum). A mineral resource describes it this way, "Labradorite can produce a colorful play of light across cleavage planes and in sliced sections called labradorescence." Labradorite tends to be a dull grey/green in color until you see the flashes. Most of the flashes you see will be blue, aqua, green, yellow/gold, and orange.

Specrolite IS labradorite. It is the labradorite with the most intense colorful flashes, the highest quality mineral specimens. If you Google Image spectrolite, you'll see it's labradorite with the flash on full blast.

Now how about larvikite?

Larvikite is a feldspar like labradorite. This means it also has the flashy properties. However, larvikite is a grey and black stone with blue and white flashes. Larvikite is known by many names, including: Birds Eye Granite, Black Moonstone, Blue Norwegian Moonstone, Blue Pearl Granite, Blue Granite, Norwegian Pearl Granite, Emerald Pearl, and Pub Stone. It is not, however, a granite or a pearl by any means. It IS related to moonstone (which is also a flashy feldspar like labradorite).

Larvikite is not spectrolite! The colors of these stones are easily distinguishable.