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| Formula | (Mg, Al, Fe)3 [(Si,Al)4O10](OH)8 | Clinochlore (Mg,Fe)5Al(Si3Al)O10(OH)8
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| Crystal System | monoclinic | Clinochore can also be triclinic |
| Crystal Habit | Pseudohexagonal tabular crystals;commonly foliated, fibrous, granular, earthy or massive; twinning common. | |
| Cleavage | Micaceous (perfect basal ) | |
| Color/Pleochroism | green-brown | |
| Optic Sign | Biaxial positive | Can also be negitive. |
| 2V | 0-50 | |
| Optic Orientation | ||
Refractive Indices |
alpha=1.57-1.66 |
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| Max Birefringence | very weak. | |
| Extinction | Inclined | |
| Distinguishing Features | Anomalous interference colors-baise/khaki color. micaceous and pseudohhexagonal. | |
| Occurrence | An important constituent of many low grade metamorphic rocks with temperatures of to 400 degrees C and pressures up to a few Kb. Typically found with feldspars, quartz, garnet, talc, serpentine, chloritoid, calcite, dolomite, actinolite, biotite, olivine, plagioclase, rutile, ilmenite, titanite, magnetite, chomite, sulfides, zircon, and zeolites. Also occurs in both metaphelites and meta-mafic igneous rocks. |
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| Editors | Sarah Cadieux (MHC '08) | |
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