BERTRANDITE


Meaning of BERTRANDITE in English

General Information:

Chemical Formula:

Be4Si2O7(OH)2

Composition:

(Molecular Weight = 238.23 gm)

Beryllium 15.13 % Be

Silicon 23.58 % Si

Hydrogen 0.85 % H

Oxygen 60.44 % O

Empirical Formula:

Be4(Si2O7)(OH)2

Environment:

Commonly found in Be-bearing pegmatites and may be derived from the alteration of beryl.

Locality:

Discovered at near Nantes, Loire-Inferieure, France. Also found at Irkutka and Altai Mountains, Siberia, Russia.

Name Origin:

Named after the French mineralogist, E. Bertrand.

Physical Properties:

Cleavage:

[001] Perfect, [110] Distinct, [101] Distinct

Color:

colorless or pale yellow.

Density:

2.59 - 2.6, Average = 2.59

Diaphaniety:

Translucent to transparent

Habits:

Crystalline - Fine - Occurs as well-formed fine sized crystals., Tabular - Form dimensions are thin in one direction., Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline ).

Hardness:

6-7 - Orthoclase-Quartz

Luminescence:

None.

Luster:

Vitreous (Glassy)

Streak:

white

More details...

Mineralogy database English vocab.      Английский словарь базы данных минералогии .