Scapolite
Scapolite Information For your gem needs see our Recommended Suppliers.
WEARABILITY* Poor
ENHANCEMENTS None
*Wearability is graded as Excellent, Very Good, Good, Poor, and Forget It!
CHEMISTRY (Na,Ca)4[Al3Si9O24]Cl
CRYSTALLOGRAPHY Tetragonal
REFRACTIVE INDEX 1.536 - 1.579
HARDNESS 6 - 6.5
SPECIFIC GRAVITY 2.50 - 2.78
CLEAVAGE Perfect in two directions
HEAT SENSITIVE No
SPECIAL CARE INSTRUCTIONS Avoid rough handling
For more details see the article on "Hardness and Wearability."
This gem, which is not widely available and little recognized by the public, is none the less, a desirable and attractive gem material for jewelers as well as collectors. It is known mineralogically as Wernerite, after its discoverer. Similar to the gems in the garnet group, this gem ranges in color and precise gemological values along a "solution series" as the amount of sodium and calcium in the chemical formula changes.
Colors range from near colorless to yellow and orange, through pinks to purple. Yellows are the most commonly found colors with purple a distant second. Irradiation of colorless or yellow specimens can create a brownish purple variety which is prone to fading and not very attractive.
The main sources are Brazil, Tanzania, Madagascar and Sri Lanka. Cat'seye stones are rather rare and desirable as they have exceptionally sharp eyes. Its hardness of 6 and cleavability necessitate some care in setting and wearing in jewelry, with daily wear ring use unwise. The name comes from the Greek "scapos" or rod, and refers to the short rod-like crystal habit.
The value of yellow scapolite, depends on size, clarity and strength of color. The usual premium on value would be expected in terms of saturation of color and custom versus native or commercial cutting. Values for natural purple or irradiated stones differ dramatically as the natural stones are both rarer and a delicate, but much purer, purple. They would range above and below the prices for yellows, respectively. The rare cat'seye varieties are highly varied and quite beautiful.
