General Information:
Chemical Formula:
(Ba,Na,K)1-2(Si,Al)8O16·6(H2O)
Composition:
(Molecular Weight = 723.89 gm)
Barium 18.97 % Ba
Aluminum 7.45 % Al
Silicon 23.28 % Si
Hydrogen 1.67 % H
Oxygen 48.62 % O
Empirical Formula:
BaAl2Si6O16·6(H2O)
Environment:
Alteration product of basalt and similar eurptive rocks.
IMA Status:
Approved IMA
Locality:
Bodenmais in Bavaria, Germany.
Name Origin:
From the Greek harmos - "I combine" and temseis - "I cut" alluding to the fact that the pyramid divides parallel to the plane that passes through the terminal edges.
Physical Properties:
Cleavage:
[010] Good, [001] Fair
Color:
white, gray, yellow, red, or brown.
Density:
2.44 - 2.5, Average = 2.46
Diaphaniety:
Subtransparent to translucent
Habits:
Twinning Common - Crystals are usually twinned., Cruciform - Twinned tabular crystals with a cross-like outline., Striated - Parallel lines on crystal surface or cleavage face.
Hardness:
4-5 - Fluorite-Apatite
Luminescence:
Fluorescent.
Luster:
Vitreous (Glassy)
Streak:
white
More details...