Tourmaline

Tourmaline shares the birthstone designation for October with Opal.tourmaline2.jpg

It is also the national gemstone of the United States, the ancient Egyptians believed it passed through a rainbow on its journey to earth, and so brought all the colors of the rainbow with it.

If you are not keen on Opals, this is a good alternative with a variety of colors to choose from.

Crystal Structure

Trigonal

Composition

Complex borosilicate

Hardness

7.5

Members of the Tourmaline family of minerals have the same basic crystal structure but come in a variety of different colors from yellow, green, pink, red (referred to as Rubellite), blue (referred to as Indicolite) and black. 

Rubellite in a ruby red color is the most highly prized, typically speaking the specific gravity for tourmaline varies with color the darker the red, the higher the specific gravity.

There is also Watermelon Tourmaline referred to as such because it is pink or red tourmaline encased in green tourmaline and likened to a slice of watermelon. A really pretty stone especially if you get one with strong color definition.

Black tourmaline these days is not used in jewelry as it is too brittle a stone, and as a gemstone is worth very little, however in Victoria times it was very popular in mourning jewelry

The most commonly found color today is yellow-green, however the stone can be as dark as emerald green and if you find one in this color it will be worth more as it is much rarer in ocurrence. (The crystal structure given on this page is for the yellow-green tourmaline).

Durability and Care

Whilst tourmaline is 7.5 on the Mohs Scale, so not as hard as say sapphire or ruby. It is still good for everyday wear, just be aware of sudden or extreme temperature changes.

It is common for blue and green tourmaline stones to be heat treated whilst Rubellite the red variety are often irradiated to intensify the color so when cleaning it is advisable to never use an ultrasonic or steam cleaner, just use warm soapy water, rinse well and dry with a soft cloth.
October – Tourmaline Color Glass Earrings available from GemstonesAndCrystals

Birthstone History and Lore

Tourmaline the alternative birthstone for October shares the birthstone designation with OpalAlso associated with the Star Sign Libra.

Tourmaline was not known by ancient magicians, so is little used in magic, however, it said to have power over love, friendship, money, health and energy among-est others. Wearing or placing a stone beneath your pillow is said to help promote astral projection.

Did you know…

Tourmaline is derived from the Sinhalese word turamali meaning “mixed” or “stone of mixed colors,” it can be bi, tri colored or parti colored. Cats-eye Tourmaline (chatoyant) can be found in several colors but particularly pink and green. Some Tourmaline can also display color-change going from yellowish-green in daylight to orange-red in incandescent light.

It can also be strongly pleochroic, which means that the stone looks to be one color face up, but if you look at the stone from different angles you will see two or more colors or tones.

That in the early 1900’s the main source for tourmaline was in Maine and California.

Tourmaline is sometimes referred to as the “electric stone” as it can become statically charged, attracting dust and lint when rubbed or heated, this is referred to as pyroelectricity. You may find your tourmaline stones and jewelry attract more dust.

Specific Gravity

3.06

Refractive Values

1.62 – 1.64

birefringence (doubly refractive gems only)

0.018

Lustre

Vitreous

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