Andesine is a plagioclase feldspar intermediate in composition between albite and anorthite.
In thin section, plagioclase feldspar grains often look like they’re sprinkled with dirt (PPL) or tiny confetti (XPL). You can find the explanation on the plagioclase feldspar page.
Physical Properties |
|
| Chemical formula | (Na,Ca)(Si,Al)4O8 |
| Class | Tectosilicate 3D framework of linked tetrahedra |
| Crystal system | Triclinic |
| Habit | Tabular Massive Granular Frequently twinned from minerals.net |
| Color | Colorless Gray Yellow-green White |
| Hardness | 7 |
| Specific gravity | 2.67 |
| Cleavage | Perfect {001}, good {010} |
| Fracture | Uneven |
| Luster | Vitreous |
| Transparency | Transparent to translucent |
| Streak | White |
Optical Properties |
|
| PPL | Colorless Non-pleochroic |
| XPL | 1st order gray |
| δ | 0.008 |
| after webmineral.com |
Andesine in Hand Sample
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Andesine in Thin Section
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