Yakhontovite Mineral Data

General Yakhontovite Information

Chemical Formula:

(Ca,K)0.5(Cu,Fe+++,Mg)2Si4O10(OH)2•3(H2O)

Composition:

Molecular Weight = 427.29 gm

Potassium 0.09 % K 0.11 % K₂O

Calcium 1.88 % Ca 2.62 % CaO

Magnesium 3.98 % Mg 6.60 % MgO

Iron 10.46 % Fe 14.95 % Fe₂O₃

Copper 11.90 % Cu 13.40 % Cu₂O

Silicon 26.29 % Si 56.25 % SiO₂

Hydrogen 0.47 % H 4.22 % H₂O

Oxygen 44.93 % O

______ ______

100.00 % 98.15 % = TOTAL OXIDE

Empirical Formula:

Ca_0.2K_0.01Cu_0.8Fe³⁺_0.8Mg_0.7Si₄O₁₀(OH)₂

Environment:

As veins and coatings in deeply oxidized sulfide-cassiterite ores.

IMA Status:

Approved IMA 1986

Locality:

Komosomolsk region, "Far Eastern Region", Russia. Link to MinDat.org Location Data.

Name Origin:

Named for Liiia KKonstantinovna Yakhontova I1926-), Russian mineralogist, University of Moscow, a specialist in cobalt deposits.

Name Pronunciation:

Yakhontovite + Pronunciation

Yakhontovite Image

Images:

Yakhontovite

Comments: Green coating of yakhontovite in matrix.
Location: Granite Gap, Hidalgo Co., New Mexico, USA. Scale: Specimen Size 2x2.5 cm.
© Diederik Visser

Yakhontovite Crystallography

Axial Ratios:

a:b:c =0.5775:1:1.5371

Cell Dimensions:

a = 5.26, b = 9.108, c = 14, Z = 2; beta = 90° V = 670.71 Den(Calc)= 2.12

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): 4.5(1), 7.3(1), 13.9(1),

Physical Properties of Yakhontovite

Cleavage:

None

Color:

Pistachio green.

Diaphaneity:

Transparent

Fracture:

Conchoidal - Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz).

Habit:

Aggregates - Made of numerous individual crystals or clusters.

Hardness:

2-3 - Gypsum-Calcite

Luster:

Earthy (Dull)

Streak:

light green

Optical Properties of Yakhontovite

Gladstone-Dale:

CI calc= -0.14 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2606,KC= 0.2287
Ncalc = 1.48

Optical Data:

Biaxial (?), a=1.53-1.545, g=1.56-1.575, bire=0.0300

Pleochroism (x):

blue greens.

Pleochroism (y):

blue greens.

Pleochroism (z):

blue greens.

Calculated Properties of Yakhontovite

Electron Density:

Bulk Density (Electron Density)=2.09 gm/cc
note: Specific Gravity of Yakhontovite =2.12 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Yakhontovite= 9.54 barns/electron
U=PE_Yakhontovite x r_electron= 19.93 barns/cc.

Radioactivity:

GRapi = 1.31 (Gamma Ray American Petroleum Institute Units)
Concentration of Yakhontovite per GRapi unit = 76.09 (%)

Estimated Radioactivity from Yakhontovite - barely detectable

Yakhontovite Classification

Dana Class:

71.03.01b.07 (71)Phyllosilicate Sheets of Six-Membered Rings

(71.03)with 2:1 clays

(71.03.01b)Smectite group (Trioctahedral Smectites)

71.03.01b.01 Sobotkite? (K,Ca0.5)0.33(Mg,Al)3(Si3Al)O10(OH)2•1-5(H2O) Unk. Mono

71.03.01b.02 Saponite (Ca/2,Na)0,3(Mg,Fe)3(Si,Al)4O10(OH)2•4(H2O) C 2/m 2/m

71.03.01b.02a Ferrosaponite! Ca0.3(Fe,Mg,Fe)3(Si,Al)4O10(OH)2•4(H2O) C? Mono

71.03.01b.03 Sauconite Na0,3Zn3(Si,Al)4O10(OH)2•4(H2O) C 2/m 2/m

71.03.01b.04 Hectorite Na0,3(Mg,Li)3Si4O10(OH)2 C 2/m 2/m

71.03.01b.05 Pimelite? Ni3Si4O10(OH)2•4(H2O) Unk. Hex

71.03.01b.06 Stevensite (Ca0.5,Na)0.33(Mg,Fe)3Si4O10(OH)2•n(H2O) Unk (ORTH ?) Mono

71.03.01b.07 Yakhontovite (Ca,K)0.5(Cu,Fe,Mg)2Si4O10(OH)2•3(H2O) C 2/m 2/m

71.03.01b.08 Zincsilite Zn3Si4O10(OH)2•4(H2O)(?) C 2/m ? 2/m

Strunz Class:

09.EC.40 09 - SILICATES (Germanates)

09.E - Phyllosilicates

09.EC -Phyllosilicates with mica sheets, composed of tetrahedral and octahedral nets

09.EC.40 Almbosite? Fe5Fe4V4Si3O27 Ortho ? Ortho

09.EC.40 Beidellite Na0.5Al2(Si3.5Al0.5)O10(OH)2•n(H2O) C 2/m or ORTH 2/m

09.EC.40 Kurumsakite (Zn,Ni,Cu)8Al8V2Si5O35•27(H2O)(?) Unk Ortho

09.EC.40 Montmorillonite (Na,Ca)0,3(Al,Mg)2Si4O10(OH)2•n(H2O) C 2/m 2/m

09.EC.40 Nontronite Na0.3Fe2(Si,Al)4O10(OH)2•n(H2O) C 2/m 2/m

09.EC.40 Volkonskoite Ca0.3(Cr,Mg,Fe)2(Si,Al)4O10(OH)2•4(H2O) C 2/m 2/m

09.EC.40 Yakhontovite (Ca,K)0.5(Cu,Fe,Mg)2Si4O10(OH)2•3(H2O) C 2/m 2/m

Other Yakhontovite Information

References:

NAME( Dana8) PHYS. PROP.(Am.Min.,Vol.76,p668,1991) OPTIC PROP.(Am.Min.,Vol.76,p668,1991)

See Also:

Links to other databases for Yakhontovite :
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

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

Yakhontovite

(Ca,K)0.5(Cu,Fe+++,Mg)2Si4O10(OH)2•3(H2O)
Dana No: 71.03.01b.07 Strunz No: 09.EC.40
Locality:

Notes: