|
|
www.mineralgallery.co.za Minerals A-E |
|
|
Charlesite |
||
Name
Charlesite
Chemistry
Ca6Al2(SO4)3(OH)12 - 26H2O, Hydrated Calcium Aluminum Sulfate Hydroxide.
Uses
As a mineral specimens.
Color
Bright yellow, also colorless and white.
Hardness
2-2.5
Specific gravity
1.7 It consist of almost just water and that is why it is so light.
Streak
White
Crystals
It will often form well shaped hexagonal prisms that are topped by a hexagonal pyramid, which in turn is often truncated by the flat face of a pinacoid.
Accompanied by:
Calcite, ettringite and sturmanite and some other zeolites
Similar to:
Sturmanite and ettringite
Charlesite is a scarce hydrated aluminum sulfate.
It is almost just water as you can see when you look at the chemical formula. Crystals are usually rather small, typically less than 1cm long. Because it is almost just water it is sensitive too direct sun and an excess of moisture. It is best not to clean your ettringite crystals with water.
Charlesite is an interesting mineral for collectors. It forms as a precipitate from hydrothermal solutions. It has a typically bright yellow color and a nice luster. It is difficult under ordinary means to distinguish charlesite from ettringite. They have similar crystal habit, density, luster and will often share the same bright yellow color.
