General Information:
Chemical Formula:
(Fe+++,Al)25(PO4)17O6(OH)12·75(H2O)
Composition:
(Molecular Weight = 4,481.51 gm)
Aluminum 3.76 % Al
Iron 23.37 % Fe
Phosphorus 11.75 % P
Hydrogen 3.64 % H
Oxygen 57.48 % O
Empirical Formula:
Fe2+18.75Al6.25(PO4)17O6(OH)12·75(H2O)
Name Origin:
From the Greek kakos, meaning "wrong" and xenos, meaning "guest.;"
Physical Properties:
Cleavage:
None
Color:
brownish yellow, green, yellow, golden yellow, or red yellow.
Density:
2.3 - 3.4, Average = 2.84
Habits:
Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite), Acicular - Occurs as needle-like crystals., Stellate - Occurs as spherical, radial aggregates radiating from a "star" like point.
Hardness:
3-3.5 - Calcite-Copper Penny
Luminescence:
None.
Luster:
Silky
Streak:
yellow
More details...