Pentahydrite Mineral Data

Pentahydrite Mineral Data +

[Mineral Specimens] [Our best] [Rare specimens] [Latest updates] [Home Page]
Fine Minerals, Moldavites, Jewellery, Meteorites and Fossils
Rockshop.cz is based in Prague, Czech republic

General Pentahydrite Information

Chemical Formula:

MgSO4·5(H2O)

Composition:

Molecular Weight = 210.45 gm

Magnesium 11.55 % Mg 19.15 % MgO

Hydrogen 4.79 % H 42.80 % H₂O

Sulfur 15.24 % S 38.05 % SO₃

Oxygen 68.42 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Mg(SO₄)·5(H₂O)

Environment:

Pseudomorphs of dehydration of epsomite.

IMA Status:

Valid Species (Pre-IMA) 1951

Locality:

The Geysers, Sonoma County, California, USA. Link to MinDat.org Location Data.

Name Origin:

Named from the Greek, penta, "five" and hydros "water" in allusion to the 5 water molecules in the formula.

Synonym:

ICSD 2776

PDF 25-532

Pentahydrite Image

Images:

Pentahydrite

Comments: White, powdery pentahydrite.
Location: Shaft 371, Schlema-Hartenstein area, Erzgebirge, Saxony, Germany. Scale: Picture size 4 mm.
© Thomas Witzke / Abraxas-Verlag

Pentahydrite Crystallography

Axial Ratios:

a:b:c =0.6004:1:0.5758

Cell Dimensions:

a = 6.335, b = 10.55, c = 6.075, Z = 2; alpha = 99.17°, beta = 109.88°, gamma = 75° V = 364.10 Den(Calc)= 1.92

Crystal System:

Triclinic - PinacoidalH-M Symbol ( 1) Space Group: P1

Crystal Structure:

Mouse
drag1 - LMB Manipulate Structure
drag2 - RMB Resize/Rotate
Keyboard
S - Stereo Pair on/off
H - Help Screen
I - Data Info
A - Atoms On/Off
P - Polyhedra On/Off
B - Bonds On/Off
Help on Above

Peterson R C , Hammarstrom J M , Seal R R , American Mineralogist , 91 (2006) p.261-269, Alpersite (Mg,Cu)SO4*7H2O, a new mineral of the melanterite group, and cuprian, pentahydrite: Their occurrence within mine waste, Locality: Big Mike mine, Nevada, USA

View Additional jPOWD Structure files for Pentahydrite
[1] [2]

Physical Properties of Pentahydrite

Cleavage:

None

Color:

White, Light blue, Light greenish blue.

Density:

1.9

Diaphaniety:

Transparent to Translucent

Habit:

Efflorescences - Crystals covering matrix, generally produced from transpiro-evaporation.

Habit:

Granular - Generally occurs as anhedral to subhedral crystals in matrix.

Hardness:

2.5 - Finger Nail

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Pentahydrite

Gladstone-Dale:

CI meas= -0.025 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= -0.014 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2547,KPDmeas= 0.2574,KC= 0.2512

Optical Data:

Biaxial (-), a=1.482, b=1.492, g=1.493, bire=0.0110, 2V(Calc)=34, 2V(Meas)=45.13.

Calculated Properties of Pentahydrite

Electron Density:

r_electron=2.01 gm/cc
note: r_Pentahydrite=1.92 gm/cc.

Fermion Index

Fermion Index = 0.01302
Boson Index = 0.98698

Photoelectric:

PE_Pentahydrite= 1.29 barns/electron
U=PE_Pentahydrite x r_electron= 2.58 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)

Pentahydrite is Not Radioactive

Pentahydrite Classification

Dana Class:

29.6.7.3 (29)Hydrated Acid and Sulfates

(29.6)where A XO4 · x(H2O)

(29.6.7)Chalchanthite Group (Triclinic: P1¯)

29.6.7.1 Chalcanthite CuSO4·5(H2O) P1 1

29.6.7.2 Siderotil FeSO4·5(H2O) P1 1

29.6.7.3 Pentahydrite MgSO4·5(H2O) P1 1

29.6.7.4 Jokokuite MnSO4·5(H2O) P1 1

Strunz Class:

VI/C.04-10 VI - Sulfates,Chromates,Molybdates and Tungstates

VI/C - Water-bearing sulfates without unfamiliar anions. cations of medium size

VI/C.04 - Chalcanthite group

VI/C.04-10 Pentahydrite MgSO4·5(H2O) P1 1

VI/C.04-20 Siderotil FeSO4·5(H2O) P1 1

VI/C.04-30 Jokokuite MnSO4·5(H2O) P1 1

VI/C.04-40 Chalcanthite CuSO4·5(H2O) P1 1

Other Pentahydrite Information

References:

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

See Also:

Links to other databases for Pentahydrite :
1 -Am. Min. Crystal Structure Database 2 -Athena 3 - Crocoite.com Mineral Locations 4 - EUROmin Project 5 -Google Images 6 -Google Scholar 7 -MinDAT 8 -MinMax(Deutsch) 9 -MinMax(English) 10 -Mineralienatlas (Deutsch) 11 -QUT Mineral Atlas 12 - WWW-MINCRYST 13 -École des Mines de Paris

Search for Pentahydrite using:

[ALTAVISTA] [AOL] [About.com] [All-The-Web] [HotBot] [Ixquick] [LookSmart] [MAMMA] [MSN.COM] [Netscape] [Teoma] [Wikipedia] [YAHOO]

Visit our Advertisers for Pentahydrite :
AA Mineral Specimens
B and L Minerals
Dan Weinrich Fine Minerals
Dan Weinrich Auctions
e-Rocks Auctions
Excalibur Minerals
Exceptional Minerals
Fabre Minerals
Greenside Minerals
John Betts Fine Minerals
Masons Minerals
Minernet.it
Mineral News
Mineral of the Month Club
MineralsWeb Fine Minerals
Rockshop.cz Kalat Fine Minerals
T G Fine Minerals
Wrights Rock Shop

Translate Pentahydrite Mineral Data :

Ask about Pentahydrite 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 Español

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

Pentahydrite

MgSO4·5(H2O)
Dana No: 29.6.7.3 Strunz No: VI/C.04-10
Locality:

Notes: