|
gptkbp:instanceOf
|
gptkb:granite
|
|
gptkbp:associatedMinerals
|
gptkb:apophyllite
gptkb:datolite
gptkb:epidote
gptkb:stilbite
|
|
gptkbp:birefringence
|
0.033–0.040
|
|
gptkbp:category
|
inosilicate
|
|
gptkbp:chemicalFormula
|
Ca2Al(AlSi3O10)(OH)2
|
|
gptkbp:cleavage
|
distinct on [001]
|
|
gptkbp:color
|
white
yellow
pale green
|
|
gptkbp:crystalSystem
|
orthorhombic
|
|
gptkbp:discoveredIn
|
gptkb:South_Africa
1788
|
|
gptkbp:event
|
hydrothermal veins
basaltic volcanic rocks
|
|
gptkbp:fluorescence
|
none
|
|
gptkbp:fracture
|
uneven
|
|
gptkbp:habit
|
botryoidal
globular
stalactitic
|
|
gptkbp:hardnessMohs
|
6–6.5
|
|
gptkbp:IMAStatus
|
approved mineral
|
|
gptkbp:luster
|
vitreous
pearly
|
|
gptkbp:namedAfter
|
gptkb:Hendrik_von_Prehn
|
|
gptkbp:opticalProperties
|
biaxial (+)
|
|
gptkbp:pleochroism
|
none
|
|
gptkbp:refractiveIndex
|
1.611–1.669
|
|
gptkbp:specificGravity
|
2.80–2.95
|
|
gptkbp:streak
|
white
|
|
gptkbp:symbol
|
Prn
|
|
gptkbp:tenacity
|
brittle
|
|
gptkbp:transparency
|
translucent
|
|
gptkbp:uses
|
gptkb:granite
collector's mineral
|
|
gptkbp:bfsParent
|
gptkb:Babingtonite
gptkb:pumpellyite
|
|
gptkbp:bfsLayer
|
6
|
|
https://www.w3.org/2000/01/rdf-schema#label
|
prehnite
|