Scapolite

Yellow rough scapolite exhibiting conchoidal fracture.

Scapolite is silicate of aluminium with calcium and sodium where potassium or fluorine may be present. Scapolite comes in almost all colors (yellow and violet are common) and is a good simulant for many natural stones including quartz, beryl, feldspar, etc.

A scapolite is cut into cabochon when parallel needle like inclusions is found within it so that it can generate cat's eye effect otherwise it is cut in facetted cut stone. The best scapolite come form Kenya, Madagascar, Brazil and Tanzania.


Properties
Chemical Composition: 
Silicate of aluminium with calcium and sodium. Potassium or fluorine may be present.
Classification / Type: 
Belongs to the Marialite (sodium rich) - Meionite (calcium rich) isomorphous series. As a result there is a wide range in properties and composition.
Colors / Varieties: 
All colors. Chatoyant varieties.
Crystal System / Forms: 
Tetragonal System / Prismatic crystals with square cross-section, massive cleavage material.
Hardness: 
6
Specific Gravity: 
Range: 2.50 - 2.78. In general, higher S.G. corresponds to higher R.I.
Cleavage / Fracture: 
Easy 2 directional / Conchoidal
Optic Character: 
Anisotropic, D.R.; Uniaxial Negative.
Lustre: 
Vitreous.
Refractive Index / Birefringence: 
1.535 - 1.542 / 0.007; 1.550 - 1.572 / 0.022. Range: 1.535 - 1.572. R.I. increases with meionite percentage. As R.I. increases birefringence increases and vice-versa.
Pleochroism: 
Distinct
Dispersion: 
0.017
Magnification: 
Parallel rod like cavities, needles, crystal and fluid inclusions, may show doubling.
U.V. Fluorescence: 
Yellow, orange in longwave and pink in shortwave; massive material may show phosphorescence.
Spectrum: 
Red, pink, violet: band at 663nm and 652nm, absorption in yellow.
Cause of Color: 
Color centers.
Treatment (Enhancement): 
Specific Tests & Remarks: 
Attacked by acids.
Synthesis: 
-
Simulants (with key separation tests): 
Quartz (optic figure / sign, U.V. fluorescence, inclusions, doubling), feldspar (optic figure, inclusions), beryl (R.I., birefringence, U.V. fluorescence, inclusions), Iolite (optic figure, pleochroism, U.V. fluorescence), Glass (optic character)
Geological Occurrence: 
Metamorphic and igneous rocks.
Sources: 
Kenya, Madagascar, Brazil, Myanmar, Tanzania, Canada.
Cuts & Uses: 
Facetted cuts.

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In Greece, people think if wine is poured into the cups made of amethyst, one does not get drunk after drinking that.

In Rome, a talisman having coral pieces is considered very auspicious to quell the bad spells of evil look. The Romans were in the habit of hanging chains made of ancient coral pieces from the cradle of the infants to protect them from evil effects.

In China, people wear rings studded with tiny conch or oyster shells as they believe it cures all aches such as stomach ache, worms and like.

In India, pendants made of silver and studded with pearls are hung from the necks of the children to save them from any bad effects.

Greeks still believe, if women wear blue sapphires then no sense of immorality would pollute their mind nor can any fear of the supernatural can trouble them.

The Pope Innocent III had circulated an order asking all the priests wear blue sapphire, so that morality can be strengthened.

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It is believed that a turquoise gifted to a friend or a lover turns his or her life into one of happiness and good luck.

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