Perloffite Mineral Data

General Perloffite Information

Chemical Formula:

Ba(Mn,Fe++)2Fe+++2(PO4)3(OH)3

Composition:

Molecular Weight = 680.92 gm

Barium 18.15 % Ba 20.27 % BaO

Calcium 1.18 % Ca 1.65 % CaO

Magnesium 0.36 % Mg 0.59 % MgO

Manganese 11.30 % Mn 14.58 % MnO

Iron 19.68 % Fe 4.22 % FeO / 23.45 % Fe₂O₃

Phosphorus 13.65 % P 31.27 % P₂O₅

Hydrogen 0.44 % H 3.97 % H₂O

Oxygen 35.24 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Ba_0.9Ca_0.2Mn²⁺_1.4Fe²⁺_0.4Mg_0.1Fe³⁺₂(PO₄)₃(OH)₃

Environment:

Secondary mineral in a complex zoned granite pegmatite.

IMA Status:

Approved IMA 1977

Locality:

Big Chief mine, one km south of Glendale, Pennington County, South Dakota, USA. Link to MinDat.org Location Data.

Name Origin:

Named for Louis Perloff (1907-), American lawyer and collector of microscopic minerals.

Name Pronunciation:

Perloffite + Pronunciation

Perloffite Image

Images:

Perloffite

Comments: Black, prismatic perloffite crystals on matrix.
Location: Big Chief mine, Keystone, Pennington County, South Dakota, USA. Scale: Not Given.
© Lou Perloff / Photo Atlas of Minerals

Perloffite Crystallography

Axial Ratios:

a:b:c =0.7424:1:0.4021

Cell Dimensions:

a = 9.223, b = 12.422, c = 4.995, Z = 2; beta = 100.39° V = 562.88 Den(Calc)= 4.02

Crystal System:

Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 2₁/m

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 3.166(1), 2.979(0.6), 3.104(0.53),

Physical Properties of Perloffite

Cleavage:

{100} Perfect

Color:

Brownish black, Greenish brown, Dark brown, Black.

Density:

3.32

Diaphaneity:

Transparent to Translucent

Habit:

Spear Head - Crystals are long, pointed and shaped like spearheads.

Hardness:

5 - Apatite

Luster:

Vitreous - Adamantine

Streak:

greenish yellow

Optical Properties of Perloffite

Gladstone-Dale:

CI meas= -0.139 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= 0.059 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1993,KPDmeas= 0.2414,KC= 0.2118
Ncalc = 1.7 - 1.85

Optical Data:

Biaxial (-), a=1.793, b=1.803, g=1.808, bire=0.0150, 2V(Calc)=70, 2V(Meas)=70-80. Dispersion r << v.

Pleochroism (x):

dark greenish brown.

Pleochroism (y):

light greenish brown.

Pleochroism (z):

dark greenish brown.

Calculated Properties of Perloffite

Electron Density:

Bulk Density (Electron Density)=3.79 gm/cc
note: Specific Gravity of Perloffite =4.02 gm/cc.

Fermion Index:

Fermion Index = 0.03
Boson Index = 0.97

Photoelectric:

PE_Perloffite= 87.05 barns/electron
U=PE_Perloffite x rElectron Density= 329.93 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Perloffite is Not Radioactive

Perloffite Classification

Dana Class:

41.09.01.04 (41)Anhydrous Phosphates, etc. Containing Hydroxyl or Halogen

(41.09)where (A B)5 (XO4)3 Zq

(41.09.01)Kulanite Group

41.09.01.01 Kulanite Ba(Fe,Mn,Mg)2Al2(PO4)3(OH)3 P 2₁/m 2/m

41.09.01.02 Penikisite BaMg2Al2(PO4)3(OH)3 P1 1

41.09.01.03 Bjarebyite (Ba,Sr)(Mn,Fe,Mg)2Al2(PO4)3(OH)3 P 2₁/m 2/m

41.09.01.04 Perloffite Ba(Mn,Fe)2Fe2(PO4)3(OH)3 P 2₁/m 2/m

41.09.01.05 Johntomaite! Ba(Fe,Ca,Mn)2Fe2(PO4)3(OH)3 P 2₁/m 2/m

Strunz Class:

08.BH.20 08 - PHOSPHATES, ARSENATES, VANADATES

08.B - Phosphates, etc. with Additional Anions, without H2O

08.BH -With medium-sized and large cations, (OH,etc.):RO4 = 1:1

08.BH.20 Bjarebyite (Ba,Sr)(Mn,Fe,Mg)2Al2(PO4)3(OH)3 P 2₁/m 2/m

08.BH.20 Kulanite Ba(Fe,Mn,Mg)2Al2(PO4)3(OH)3 P 2₁/m 2/m

08.BH.20 Penikisite BaMg2Al2(PO4)3(OH)3 P1 1

08.BH.20 Perloffite Ba(Mn,Fe)2Fe2(PO4)3(OH)3 P 2₁/m 2/m

08.BH.20 Johntomaite! Ba(Fe,Ca,Mn)2Fe2(PO4)3(OH)3 P 2₁/m 2/m

Other Perloffite Information

References:

NAME( AntBidBlaNic4) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(AntBidBlaNic4)

See Also:

Links to other databases for Perloffite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - GeoScienceWorld
6 - Google Images
7 - Google Scholar
8 - Handbook of Mineralogy (MinSocAm)
9 - Handbook of Mineralogy (UofA)
10 - MinDAT
11 - Mineralienatlas (Deutsch)
12 - Online Mineral Museum
13 - QUT Mineral Atlas
14 - Ruff.Info
15 - WWW-MINCRYST

Search for Perloffite using:

[AOL] [Bing] [Dog Pile] [GeoScienceWorld] [HotBot] [Ixquick] [Lycos] [MAMMA] [Scirus] [Teoma] [WebCrawler] [Wikipedia] [YAHOO]

Visit our Advertisers for Perloffite :

Ask about Perloffite here :
Ask-A-Mineralogist from the Mineralogical Society of America
Mindat.org's Discussion Groups
Original Rockhounds Discussion Group
Rockhounds Discussion Group on Yahoo Groups
Mineral Discussion Forum from Fabre Minerals - also available in Espa�ol

Print or Cut-and-Paste your Perloffite Specimen Label here :

Perloffite

Ba(Mn,Fe++)2Fe+++2(PO4)3(OH)3
Dana No: 41.09.01.04 Strunz No: 08.BH.20
Locality:

Notes:

Dakota Matrix
Excalibur Minerals
Exceptional Minerals
Hudson Insitute
John Betts Fine Minerals
Mc Dougall Minerals
Mineral News
Rock and Mineral Shows
Weinrich Minerals, Inc.