Skapoliitti, kirkas harvinaisuus
|Mitat :||12 x 10 x 5,5mm|
|Ominaista :||kirkas väritön|
|Erikoista :||harvinainen kirkas kivi|
|KLIKKAA KUVAA, NIIN NÄKYY TARKEMPANA !|
|Scapolite is a silicate of Aluminum which cyrstallizes in the tetragonal system with prismatic habit. The crystals are usually found in association with metamorphic rocks. Yellow appears to be the more common color for this material but some stones are colorless and some are violet or purple. Other colors, include white, greenish, gray, brown, reddish brown and pink. There is also a lavender scapolite that is produced by heat treatment but the other colors are typically untreated.|
Scapolite was discovered in 1913 in the Mogok Stone Tract of upper Myanmar where it occurs as white, pink, or violet distinctly fibrous stones. More recently it has also been discovered throughout East Africa in Kenya, Tanzania, and Mozambique. Some other occurrences are in Canada, USA, Norway, Italy, and Switzerland.
|Color Key:||white, yellow, violet,pink|
|Refractive Index:||1.54 - 1.577|
|Chemical Composition:||Na4Al3Si9O24Cl /CA4Al6Si6O24CO3|
|Ocurrence:||Kenya, Mozambique, Tanzania, Madagascar, Burma, Brazil, Canada.|
|Scapolite, which is Greek for "rod" or "shaft," is commonly found in stubby to long prismatic tetragonal crystals with a square or octahedral cross-sections. Scapolite has a density of 2.57-2.74 and a refractive index of 1.540-1.579 which is identical to quartz.|
Faceted purple scapolite can be especially difficult to differentiate from amethyst because the specific gravity and refractive index are identical. Without specialized high tech analytical equipment, the only way to separate the stones is with a plot of the optic character.
With a hardness of 6, scapolite will take a good polish and produce bright and brilliant stones. Faceted yellow brownish cabochon cats eyes are not uncommon and relatively inexpensive while large the purple stones recently discovered in Tanzania are rather expensive due to their attractive color and rarity.
Scapolite, is a sodium calcium aluminum silicate with a rather complex chemical composition. Scapolite is actually the name of an isomorphic mineral series ranging from the sodium chloride rich mineral known as Marialite (Na4CL(Al3Si 9O24) to the calcium carbonate rich mineral referred to as Meionite (Ca4(SO4CO3)( (Al6Si 6O24).