A component of bog iron ores; a cement in clays, sands, and bone material; an alteration product of triphylite in granite pegmatites.
Valid Species (Pre-IMA) 1841
Many localities are known; some with well-studied material include: in the Hrbek mine, Svata Dobrotiva (St. Benigna), near Beroun, Czech Republic. In Germany, from the Eleonore and Rot
Link to MinDat.org Location Data.
For its occurrence near Beroun (formerly Beraun), Czech Republic.
Dbl Clk - Start-Stop Rotation
RMB - Cycle Display Modes
Drag1 - Manipulate Crystal
Drag2 - Resize Keyboard
S - Stereo
I - Indicies
<space> - Start-Stop Rotation
F - Fit to Screen
M - Menu
Help on Above
( 1 1 1) ( 1 0 0) ( 0 0 1)
Warning: this java applet does not work in some browsers because of security restrictions.
Physical Properties of Beraunite
Green, Greenish brown, Gray green, Dark greenish brown, Dark red.
Druse - Crystal growth in a cavity which results in numerous crystal tipped surfaces.
Globular - Spherical, or nearly so, rounded forms (e.g. wavellite).
Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite)
2 - Gypsum
Vitreous - Dull
Optical Properties of Beraunite
CI meas= -0.031 (Excellent) - where the CI = (1-KPDmeas/KC) CI calc= -0.049 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2779,KPDmeas= 0.2731,KC= 0.2649 Ncalc = 1.76 - 1.77