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Centreville, Culpeper Basin, Fairfax Co., Virginia, USA
© 2002 John H. Betts
|System:||Tetragonal||Hardness:||4 - 5|
|Name:||From the Greek for "away from" (ἀπό, apo) and "leaf" (φύλλον, phyllos), in allusion to the way it exfoliates upon heating. The "-(KOH) suffix documents the dominant and distinctive components in this member of the Apophyllite family (potassium and hydroxide).|
Classification of Apophyllite-(KOH)
|Strunz 8th edition ID:||8/H.01-30|
|Nickel-Strunz 10th (pending) edition ID:||9.EA.15|
9 : SILICATES (Germanates)
E : Phyllosilicates
A : Single nets of tetrahedra with 4-, 5-, (6-), and 8-membered rings
|Hey's CIM Ref.:||17.1.6|
17 : Silicates Containing other Anions
1 : Silicates with fluoride (not containing Al)
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Type Occurrence of Apophyllite-(KOH)
|Type Locality:||Ore Knob Mine, Ore Knob, Ashe Co., North Carolina, USA|
|Year of Discovery:||1978|
Physical Properties of Apophyllite-(KOH)
|Hardness (Mohs):||4 - 5|
Crystallography of Apophyllite-(KOH)
|Cell Parameters:||a = 8.97Å, c = 15.83Å|
|Ratio:||a:c = 1 : 1.765|
|Unit Cell Volume:||V 1,273.70 Å³ (Calculated from Unit Cell)|
|X-Ray Powder Diffraction:|
Radiation - Copper Kα
Data courtesy of RRUFF project at University of Arizona, used with permission.
Optical Data of Apophyllite-(KOH)
|RI values:||nω = 1.542 nε = 1.543|
|Maximum Birefringence:||δ = 0.001|
Chart shows birefringence interference colour range (at 30µm thickness) and does not take into account mineral colouration.
Chemical Properties of Apophyllite-(KOH)
|Essential elements:||Ca, H, K, O, Si|
|All elements listed in formula:||Ca, F, H, K, O, Si|
Relationship of Apophyllite-(KOH) to other Species
|Series:||Forms a series with Apophyllite-(KF) (see here)|
|Related Minerals - Nickel-Strunz Grouping):|
|Related Minerals - Hey's Index Grouping:|
Other Names for Apophyllite-(KOH)
|Health Warning:||No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.|
References for Apophyllite-(KOH)
Dunn, P. J., Rouse, R. C. & Norberg, J. A. (1978): Hydroxyapophyllite, a new mineral and a redefinition of the apophyllite group. American Mineralogist 63, 196-202.
Dunn, P. J. & Wilson, W. E. (1978): Nomenclature revision in the apophyllite group: hydroxyapophyllite, apophyllite, fluorapophyllite. Min. Record 9, 95-98.
Acta Crystallographica: (1987): B43: 517.
Internet Links for Apophyllite-(KOH)
|Specimens:||The following Apophyllite-(KOH) specimens are currently listed for sale on minfind.com.|
Localities for Apophyllite-(KOH)
The map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.
(TL) indicates type locality. ? indicates mineral may be doubtful at this locality. All other localities listed without reference should be considered as uncertain and unproven until references can be found.
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