Ecuador Lapis Lazuli Birthstone Gold Diamond Girl Fashion Jewellery 13

Ecuador Lapis Lazuli Birthstone Gold Diamond Girl Fashion Jewellery. 

By Aamir Mannan

Data Value

Name Lapis Lazuli

Is a Variety of Lazurite

Crystallography Isometric;  Crystals very rare, dodecahedral, up to about 2 inches in size. Also massive, compact, disseminated, in veins.

Refractive Index 1.50 - 1.55

Luster Dull.

Hardness (?) 5-6 (depending on impurity content).

Density Pure: 2.38-2.45. gem lapis: 2.7-2.9 or higher if much pyrite present.

Cleavage Imperfect; none in massive material. Fracture uneven.

Stone Sizes Rough blocks from Afghanistan, of fine color, are known up to 100 kg. One block of Chilean material, found in a Peruvian grave, was 24 x 12 x 8 inches. A 40.5 cm tall vase of fine blue material is in the Pitti Palace, Florence, Italy.

Heat Sensitivity No

Luminescence Orange spots or streaks in LW (Afghanistan and Chile), dimmer and more pink in SW. X-rays cause yellowish glow in streaks. May fluoresce whitish in SW,

Wearability (?) * Good
Enhancements Dying, common
Special Care Instructions Avoid contact with chemicals
Formula (Na,Ca)8(Al,Si)12O24(S,SO4)
STREAK: Light blue.