Etymology
Derived from the Greek word “eu” well and “klasis” break; showing internal cracks that cause its characteristic glow, highlighting the features of this gem.
Geological Origin
The euclase is found mainly in granitic pegmatites within greisen deposits and in the chlorite-schist ones associated with topaz.
Deposits
Among the most important deposits are the ones in Brazil (Gerais Mine), Russia (Urals), Republic of Congo, Zimbabwe, and Tanzania. Colombia produces euclase in small amounts but of good quality.
Euclase Characteristics and Properties
| Mineral Type | Group IX Silicates (Nesosilicates) |
|---|---|
|
Color |
Colorless, sea green, light blue, dark blue |
|
Streak |
white |
|
Hardness |
7.5Mohs |
|
Specific Gravity |
3.10 |
|
Cleavage |
Perfect |
|
Fracture |
Conchoidal |
|
Crystal System |
Monoclinic |
|
Habit |
Elongated striated prisms |
|
Chemical Formula |
BeAl[OH l SiO4] |
|
Optical Properties |
Biaxial (+) |
|
Transparency |
Transparent |
|
Luster |
Vitreous |
|
Refractive Index |
1.650 – 1.677 |
|
Birefringence |
0.019 a 0.025 |
|
Dispersion |
0.016 (BG), 0.09 (CF) |
|
Pleochroism |
Very weak,green white, green yellow, green blue |
|
Fluorescence |
Weak or none |
Euclase False Names
The euclase can usually be confused with the aquamarine, the beryl, the hiddenite, and the sapphire. Due to its low hardness, the euclase is a difficult gem to cut and polish. It is recommended to be identified by their high birefringence.
Uses
Given its rarity it is a gem collection. Also, since 20% of the gem is beryllium it is acquired in order to combine it with different types of alloys to generate electrical wiring.
