Roscoelite Mineral Data

Roscoelite Mineral Data +

General Roscoelite Information

Chemical Formula:

K(V,Al,Mg)2AlSi3O10(OH)2

Composition:

Molecular Weight = 411.01 gm

Potassium 9.51 % K 11.46 % K₂O

Magnesium 2.37 % Mg 3.92 % MgO

Aluminum 10.50 % Al 19.85 % Al₂O₃

Vanadium 9.92 % V 17.70 % V₂O₅

Silicon 20.50 % Si 43.86 % SiO₂

Hydrogen 0.49 % H 4.38 % H₂O

Oxygen 46.71 % O

______ ______

100.00 % 101.17 % = TOTAL OXIDE

Empirical Formula:

KV⁵⁺_0.8Al_0.6Mg_0.4AlSi₃O₁₀(OH)₂

Environment:

An early stage gangue material in low-temperature epithermal Au-Ag-Te deposits and from the oxidized portions of sedimentary U-V ores.

IMA Status:

Valid Species (Pre-IMA) 1876

Locality:

Stuckslacker mine, 2 miles SW of Coloma, El Dorado Co., California. Link to MinDat.org Location Data.

Name Origin:

Named for Henry Enfield Roscoe (1833-1915) of Manchester, England who first prepared pure vanadium.

Roscoelite Image

Images:

Roscoelite

Comments: Dull olive green fine grained roscoelite cementing sandstone.
Location: Rifle Mine, Garfield County, Colorado, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Roscoelite Crystallography

Axial Ratios:

a:b:c =0.5786:1:1.1276

Cell Dimensions:

a = 5.26, b = 9.09, c = 10.25, Z = 2; beta = 101° V = 481.08 Den(Calc)= 2.84

Crystal System:

Monoclinic - PrismaticH-M Symbol (2/m) Space Group: C 2/m

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

By Intensity(I/I_o): 10(1), 3.35(0.8), 4.54(0.8),

Physical Properties of Roscoelite

Cleavage:

[001] Perfect

Color:

Brown green, Greenish brown, Yellow green, Dark brown, Dark green.

Density:

2.97

Diaphaniety:

Translucent

Habit:

Massive - Uniformly indistinguishable crystals forming large masses.

Habit:

Micaceous - Platy texture with "flexible" plates.

Habit:

Scaly - Morphology like fish scales.

Hardness:

2.5 - Finger Nail

Luminescence:

Non-fluorescent.

Luster:

Pearly

Streak:

greenish white

Optical Properties of Roscoelite

Gladstone-Dale:

CI meas= 0.089 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= 0.047 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2265,KPDmeas= 0.2166,KC= 0.2377

Optical Data:

Biaxial (-), a=1.59-1.61, b=1.63-1.685, g=1.64-1.704, bire=0.0500-0.0940

Pleochroism (x):

green brown.

Pleochroism (y):

olive green.

Pleochroism (z):

olive green.

Calculated Properties of Roscoelite

Electron Density:

r_electron=2.81 gm/cc
note: r_Roscoelite=2.84 gm/cc.

Fermion Index

Fermion Index = 0.01242
Boson Index = 0.98758

Photoelectric:

PE_Roscoelite= 3.96 barns/electron
U=PE_Roscoelite x r_electron= 11.10 barns/cc.

Radioactivity:

GRapi = 135.57 (Gamma Ray American Petroleum Institute Units)

Estimated Radioactivity from Roscoelite - barely detectable

Roscoelite Classification

Dana Class:

71.2.2a.4 (71)Phyllosilicate Sheets of Six-Membered Rings

(71.2)with 2:1 Layers

(71.2.2a)Mica Group (Muscovite subgroup)

71.2.2a.1 Muscovite KAl2(Si3Al)O10(OH,F)2 C 2/m 2/m

71.2.2a.2 Paragonite NaAl2(Si3Al)O10(OH)2 C 2/c,Cc Mono

71.2.2a.3 Chernykhite (Ba,Na)V,Al)2(Si,Al)4O10(OH)2 C 2/c 2/m

71.2.2a.4 Roscoelite K(V,Al,Mg)2AlSi3O10(OH)2 C 2/m 2/m

71.2.2a.5 Glauconite (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2 C 2/m 2/m

71.2.2a.6 Celadonite K(Mg,Fe)(Fe,Al)[Si4O10](OH)2 C 2/m 2/m

71.2.2a.6b Ferroceladonite! K2FeFeSi8O20(OH)4 C 2/m 2/m

71.2.2a.6c Ferro-aluminoceladonite! K2Fe2Al2Si8O20(OH)4 C 2/m 2/m

71.2.2a.6d Aluminoceladonite! KAl(Mg,Fe)[]Si4O10(OH)2 2/m

71.2.2a.6e Chromceladonite! KCrMg(Si4O10)(OH)2 C 2 2

71.2.2a.7 Tobelite (NH4,K)Al2(Si3Al)O10(OH)2 C 2/m 2/m

71.2.2a.8 Nanpingite Cs(Al,Mg,Fe,Li)2(Si3Al)O10(OH,F)2 C 2/c 2/m

71.2.2a.9 Boromuscovite KAl2(Si3B)O10(OH,F)2 C 2/m 2/m

71.2.2a.10 Montdorite (K,Na)(Fe,Mn,Mg)2.5[Si4O10](F,OH)2 C 2/c 2/m

71.2.2a.11 Chromphyllite! (K,Ba)(Cr,Al)2[AlSi3O10](OH,F)2 C 2c 2/m

71.2.2a.12 Shirokshinite! K(NaMg2)Si4O10F2 C 2/m 2/m

Strunz Class:

VIII/H.10-90 VIII - Silicates

VIII/H - Phyllosilicates (layered) Mica like layered silicates with [Si4O10]4- and related groups

VIII/H.10 - Mica group, Muscovite series

VIII/H.10-10 Aluminoceladonite! KAl(Mg,Fe)[]Si4O10(OH)2 2/m

VIII/H.10-20 Ferro-aluminoceladonite! K2Fe2Al2Si8O20(OH)4 C 2/m 2/m

VIII/H.10-30 Celadonite K(Mg,Fe)(Fe,Al)[Si4O10](OH)2 C 2/m 2/m

VIII/H.10-35 Chromceladonite! KCrMg(Si4O10)(OH)2 C 2 2

VIII/H.10-40 Ferroceladonite! K2FeFeSi8O20(OH)4 C 2/m 2/m

VIII/H.10-50 Paragonite NaAl2(Si3Al)O10(OH)2 C 2/c,Cc Mono

VIII/H.10-60 Boromuscovite KAl2(Si3B)O10(OH,F)2 C 2/m 2/m

VIII/H.10-70 Muscovite KAl2(Si3Al)O10(OH,F)2 C 2/m 2/m

VIII/H.10-80 Chromphyllite! (K,Ba)(Cr,Al)2[AlSi3O10](OH,F)2 C 2c 2/m

VIII/H.10-90 Roscoelite K(V,Al,Mg)2AlSi3O10(OH)2 C 2/m 2/m

VIII/H.10-95 Ganterite! [Ba0.5(Na,K)0.5]Al2(Si2.5Al1.5O10)(OH)2 C 2/c 2/m

VIII/H.10-100 Tobelite (NH4,K)Al2(Si3Al)O10(OH)2 C 2/m 2/m

VIII/H.10-110 Nanpingite Cs(Al,Mg,Fe,Li)2(Si3Al)O10(OH,F)2 C 2/c 2/m

Other Roscoelite Information

References:

NAME( MinRec) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(AntBidBlaNic2)

Search for Roscoelite using:

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

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

Translate Roscoelite Mineral Data :

Ask about Roscoelite 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 Roscoelite Specimen Label here :

Roscoelite

K(V,Al,Mg)2AlSi3O10(OH)2
Dana No: 71.2.2a.4 Strunz No: VIII/H.10-90
Locality:

Notes: