Amphibole
Mineral Name
|
Tremolite |
Actinolite
|
Hornblende
|
Crystal System
|
Monoclinic |
Monoclinic |
Monoclinic |
Chemical Comp..
|
Ca2Mg5Si8O22(OH,F)2 |
Ca2(Mg,Fe)5Si8O22(OH,F)2 |
Complex!
|
Color
|
Colorless
to Gray
|
Green |
Green
- Brown
|
Pleochroism
|
None
|
Strong-Green |
Strong Green-Brown
|
Cleavage
|
2@60˚
& 120˚ in basal
|
2@60˚
& 120˚ in basal |
2@60˚ & 120˚ in basal
|
Relief
|
Moderate |
Moderate
|
Moderate
|
Birefringence
|
Moderate-High 1st Order |
Moderate-High 1st Order |
Moderate-High 1st Order
|
| 2V |
86˚
|
76˚
|
95˚-27˚
|
| Optic Sign |
Negative |
Negative |
Negative or Positive
|
Twinning
|
Simple or Lamellar
|
Simple or Lamellar |
Simple or Lamellar
|