Brandtite Mineral Data

General Brandtite Information

Chemical Formula:

Ca2(Mn,Mg)(AsO4)2•2(H2O)

Composition:

Molecular Weight = 441.30 gm

Calcium 18.16 % Ca 25.41 % CaO

Magnesium 1.38 % Mg 2.28 % MgO

Manganese 9.34 % Mn 12.06 % MnO

Arsenic 33.95 % As 52.08 % As₂O₅

Hydrogen 0.91 % H 8.16 % H₂O

Oxygen 36.25 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Ca₂Mn²⁺_0.75Mg_0.25(AsO₄)₂•2(H₂O)

IMA Status:

Valid Species (Pre-IMA) 1888

Locality:

Harstig mine, Pajsberg near Persberg, Varmland, Sweden. Link to MinDat.org Location Data.

Name Origin:

Named for Georg Brandt (1694-1768), Swedish chemist.

Name Pronunciation:

Brandtite + Pronunciation

Synonym:

ICSD 36235

PDF 29-348

Brandtite Image

Images:

Brandtite

Comments: Clear, crystalline brandtite aggregates.
Location: Harstig mine, Pajsberg, Varmland, Sweden. Scale: Size Not Given.
© Lou Perloff / Photo Atlas of Minerals

Brandtite Crystallography

Axial Ratios:

a:b:c =0.4548:1:0.4383

Cell Dimensions:

a = 5.899, b = 12.968, c = 5.684, Z = 2; beta = 108.05° V = 413.42 Den(Calc)= 3.54

Crystal System:

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

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

By Intensity(I/I_o): 3.01(1), 3.241(0.7), 3.373(0.55),

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Forms: ( 1 2 0) ( 0 1 0) ( 1 1 0) ( 1 2 2) ( 1 0 0)

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Physical Properties of Brandtite

Cleavage:

{010} Perfect, {001} Good

Color:

Colorless, White.

Density:

3.67

Diaphaneity:

Transparent to Translucent

Habit:

Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).

Habit:

Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite)

Habit:

Striated - Parallel lines on crystal surface or cleavage face.

Hardness:

3.5 - Copper Penny

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Brandtite

Gladstone-Dale:

CI meas= -0.005 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.042 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.202,KPDmeas= 0.1949,KC= 0.1938
Ncalc = 1.69 - 1.71

Optical Data:

Biaxial (+), a=1.707-1.709, b=1.711, g=1.724-1.729, bire=0.0170-0.0200, 2V(Calc)=38-60, 2V(Meas)=23. Dispersion r < v strong.

Calculated Properties of Brandtite

Electron Density:

Bulk Density (Electron Density)=3.52 gm/cc
note: Specific Gravity of Brandtite =3.67 gm/cc.

Fermion Index:

Fermion Index = 0.0017974823
Boson Index = 0.9982025177

Photoelectric:

PE_Brandtite= 27.68 barns/electron
U=PE_Brandtite x rElectron Density= 97.49 barns/cc.

Radioactivity:

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

Brandtite Classification

Dana Class:

40.02.03.02 (40)Hydrated Phosphates, etc

(40.02)where A++ (B++)2 (XO4) ï¿½ x(H2O)

(40.02.03)Roselite Subgroup (Monoclinic: P21/c)

40.02.03.01 Roselite Ca2(Co,Mg)(AsO4)2•2(H2O) P 2₁/c 2/m

40.02.03.02 Brandtite Ca2(Mn,Mg)(AsO4)2•2(H2O) P 2₁/c 2/m

40.02.03.03 Zincroselite Ca2Zn(AsO4)2•2(H2O) P 2₁/c 2/m

40.02.03.04 Wendwilsonite Ca2(Mg,Co)(AsO4)2•2(H2O) P 2₁/c 2/m

40.02.03.05 Manganlotharmeyerite! Ca(Mn,Mg,)2(AsO4)2(OH,H2O)2 C 2/m 2/m

Strunz Class:

08.CG.10 08 - PHOSPHATES, ARSENATES, VANADATES

08.C - Phosphates without Additional Anions, with H2O

08.CG -With large and medium-sized cations, RO4:H2O = 1:1

08.CG.10 Brandtite Ca2(Mn,Mg)(AsO4)2•2(H2O) P 2₁/c 2/m

08.CG.10 Roselite Ca2(Co,Mg)(AsO4)2•2(H2O) P 2₁/c 2/m

08.CG.10 Roselite-beta Ca2(Co,Mg)(AsO4)2•2(H2O) P 1 or P1 Tri

08.CG.10 Zincroselite Ca2Zn(AsO4)2•2(H2O) P 2₁/c 2/m

08.CG.10 Wendwilsonite Ca2(Mg,Co)(AsO4)2•2(H2O) P 2₁/c 2/m

Other Brandtite Information

References:

NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Dana8)

See Also:

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

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

Brandtite

Ca2(Mn,Mg)(AsO4)2•2(H2O)
Dana No: 40.02.03.02 Strunz No: 08.CG.10
Locality:

Notes:

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