Danburite

Danburite is a crystalline mineral similar to topaz. Its chemical formula is CaB2(SiO2)2. It has a Mohs hardness of 7 to 7.5 and a specific gravity of 3.0. The mineral has an orthorhombic crystal form. It is usually colourless, like quartz, but can be also either pale yellow, yellowish-brown, or pink. It typically occurs in contact metamorphic rocks.
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(n.)
A borosilicate of lime, first found at Danbury, Conn. It is near the topaz in form.
  

General Information:
 Chemical Formula:
CaB2(SiO4)2
 Composition:
(Molecular Weight = 245.86 gm)
Calcium 16.30 % Ca
Silicon 22.85 % Si
Boron 8.79 % B 
Oxygen 52.06 % O 
 Empirical Formula:
CaB2Si2O8
 Environment:
Contact metamorphic rocks.
 Locality:
Danbury, Connecticut.
 Name Origin:
Named after its location.
Physical Properties:
 Cleavage:
[001] Poor
 Color:
colorless, white, gray, brownish white, or straw yellow.
 Density:
2.97 - 3.02, Average = 2.99
 Diaphaniety:
Transparent to translucent
 Habits:
Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline)., Disseminated - Occurs in small, distinct particles dispersed in matrix., Euhedral Crystals - Occurs as well-formed crystals showing good external form.
 Hardness:
7 - Quartz
 Luminescence:
Fluorescent.
 Luster:
Vitreous - Greasy
 Streak:
white
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