Hendersonite

General Information:
 Chemical Formula:
Ca1.3V6O16·6(H2O)
 Composition:
(Molecular Weight = 721.83 gm)
Calcium 7.22 % Ca
Vanadium 42.34 % V 
Hydrogen 1.68 % H 
Oxygen 48.76 % O 
 Empirical Formula:
Ca1.3V5+6O16·6(H2O)
 Environment:
Sandstone-hosted uranium-vanadium deposits.
 IMA Status:
Approved IMA 1962
 Locality:
Eastside mines in San Juan County, New Mexico.
 Name Origin:
Named after Edward P. Henderson of the U.S. National Museum, in recognition of his mineralogical studies of the vanadium-uranium deposits of the Colorado Plateau.
Physical Properties:
 Color:
greenish black or black.
 Density:
2.77 - 2.79, Average = 2.78
 Habits:
Microscopic Crystals - Crystals visible only with microscopes., Bladed - Aggregates of thin lath-like crystals (e.g. kyanite)., Fibrous - Crystals made up of fibers.
 Hardness:
2.5 - Finger Nail
 Luster:
Adamantine - Pearly
 Streak:
brownish green
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