Lapis

Name:

Lapis Lazuli (Lazurite)

Chem:

(Na,Ca)8(Al,Si)12O24S2 - FeS - CaCO3
Sodium Calcium AluminoSilicate - (with pyrite&calcite)

Crystal:

Isometric (usually not crystalline, instead aggregate masses)

Color:

blue

Refrac. Index:

1.50

Birefraction:

None

Hardness:

5 - 6

Spec. Grav.:

2.4 - 2.9

Fracture:

conchoidal

Cleavage:

none

Environment:

lazurite is the primary mineral, but lapis lazuli is a physical mixture of calcite, pyrite, lazurite and other minerals to a lesser degree. Found as veins in limestone, and created at the contact metamorphic zone of marbles.

Association:

pyrite, calcite, augite, diopside, hornblende

Locals:

| Afghanistan | Chile | Russia | Calif., USA |

Misc:

The names comes from the Persian "lazuward", meaning "blue". It was the main coloring agent for ultramarine blue pigment, but has now been surpassed by synthetic colorants. It is easily damaged by both acids and strong base.

Gem info:

Lapis has been mined for more than a thousand years as an ornamental stone, and was found in the possessions of Tutankhamen. It is usually cut into cabochons, or geometric shapes. It is also prized for carving. About on par with turquoise and jade in price.

rectangle

faceted

rectangle2

pyramids


Name:	Lapis Lazuli (Lazurite)
Chem:	(Na,Ca)8(Al,Si)12O24S2 - FeS - CaCO3 Sodium Calcium AluminoSilicate - (with pyrite&calcite)
Crystal:	Isometric (usually not crystalline, instead aggregate masses)
Color:	blue
Refrac. Index:	1.50		Birefraction:	None
Hardness:	5 - 6		Spec. Grav.:	2.4 - 2.9
Fracture:	conchoidal		Cleavage:	none
Environment:	lazurite is the primary mineral, but lapis lazuli is a physical mixture of calcite, pyrite, lazurite and other minerals to a lesser degree. Found as veins in limestone, and created at the contact metamorphic zone of marbles.
Association:	pyrite, calcite, augite, diopside, hornblende
Locals:	\| Afghanistan \| Chile \| Russia \| Calif., USA \|
Misc:	The names comes from the Persian "lazuward", meaning "blue". It was the main coloring agent for ultramarine blue pigment, but has now been surpassed by synthetic colorants. It is easily damaged by both acids and strong base.
Gem info:	Lapis has been mined for more than a thousand years as an ornamental stone, and was found in the possessions of Tutankhamen. It is usually cut into cabochons, or geometric shapes. It is also prized for carving. About on par with turquoise and jade in price.
	rectangle	faceted	rectangle2	pyramids