Fairchildite Mineral Data

General Fairchildite Information

Chemical Formula:

K2Ca(CO3)2

Composition:

Molecular Weight = 238.29 gm

Potassium 32.82 % K 39.53 % K₂O

Calcium 16.82 % Ca 23.53 % CaO

Carbon 10.08 % C 36.94 % CO₂

Oxygen 40.29 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

K₂Ca(CO₃)₂

Environment:

Dimorph with butschliite. The samples are fused wood-ash clinkers that occurs in partly burned fir and hemlock trees in many national parks and forest in the western United States.

IMA Status:

Valid Species (Pre-IMA) 1949

Locality:

Link to MinDat.org Location Data.

Name Origin:

Named after John Gifford Fairchild (1882-1965), analytical chemist at the U. S. Geological Survey.

Name Pronunciation:

Fairchildite + Pronunciation

Synonym:

ICSD 100845

PDF 21-1287

Fairchildite Image

Images:

Fairchildite

Comments: PPL thin-section image of fused wood-ash stone, showing slightly altered lath-shaped cross-sections of fairchildite in a fine groundmass containing buetschliite and calcite. Inset image shows sample.
Location: Kaniksu National Forest, Idaho. (AmMin, v32:607). Scale: Thin Section 30 X.
© American Mineralogist

Fairchildite Crystallography

Axial Ratios:

a:c = 1:2.51896

Cell Dimensions:

a = 5.272, c = 13.28, Z = 2; V = 319.65 Den(Calc)= 2.48

Crystal System:

Hexagonal - Dihexagonal DipyramidalH-M Symbol (6/m 2/m 2/m) Space Group: P 6₃/mmc

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

By Intensity(I/I_o): 3.19(1), 2.64(0.8), 6.64(0.5),

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

Pertlik F , Zeitschrift fur Kristallographie , 157 (1981) p.199-205, Structural investigations of synthetic fairchildite, K2Ca(CO3)2, Locality: synthetic, Note: y(O1) changed to satisfy symmetry constraints

Physical Properties of Fairchildite

Cleavage:

{0001} Good

Color:

Colorless.

Density:

2.446

Diaphaneity:

Transparent

Habit:

Platy - Sheet forms (e.g. micas).

Hardness:

2.5 - Finger Nail

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Fairchildite

Gladstone-Dale:

CI meas= -0.008 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.006 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2036,KPDmeas= 0.2065,KC= 0.2048
Ncalc = 1.5 - 1.51

Optical Data:

Uniaxial (-), e=1.478, w=1.532, bire=0.0540.

Calculated Properties of Fairchildite

Electron Density:

Bulk Density (Electron Density)=2.46 gm/cc
note: Specific Gravity of Fairchildite =2.48 gm/cc.

Fermion Index:

Fermion Index = 0.0015686955
Boson Index = 0.9984313045

Photoelectric:

PE_Fairchildite= 5.47 barns/electron
U=PE_Fairchildite x r_electron= 13.44 barns/cc.

Radioactivity:

GRapi = 468.92 (Gamma Ray American Petroleum Institute Units)
Concentration of Fairchildite per GRapi unit = 0.21 (%)

Estimated Radioactivity from Fairchildite - barely detectable

Fairchildite Classification

Dana Class:

14.03.03.01 (14)Anhydrous Carbonates

(14.03)with Compound Formula A+2 B++ (CO3)2

(14.03.03)Fairchildite Series

14.03.03.01 Fairchildite K2Ca(CO3)2 P 6₃/mmc 6/m 2/m 2/m

14.03.03.02 Zemkorite (Na,K)2Ca(CO3)2 P 6₃/mmc, P 6₃mc, P 6₂c- Hex

Strunz Class:

05.AC.20 05 - CARBONATES (NITRATES)

05.A - Carbonates without additional anions, without H2O

05.AC -Alkali and alkali-earth carbonates

05.AC.20 Fairchildite K2Ca(CO3)2 P 6₃/mmc 6/m 2/m 2/m

Other Fairchildite 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 Fairchildite :
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 Fairchildite using:

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

Visit our Advertisers for Fairchildite :

A Bijoux Google Search for Fairchildite
Adam's Minerals Google Search for Fairchildite
Cape Minerals Google Search for Fairchildite
Dakota Matrix Minerals Google Search for Fairchildite
Excalibur Mineral Corp. Google Search for Fairchildite
Exceptional Minerals Google Search for Fairchildite
John Betts Fine Minerals Search for Fairchildite
McDougall Minerals Google Search for Fairchildite
Mineral News Website Link
Rock and Mineral Shows Google Search for Fairchildite
Weinrich Minerals, Inc. Google Search for Fairchildite

Ask about Fairchildite 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 Fairchildite Specimen Label here :

Fairchildite

K2Ca(CO3)2
Dana No: 14.03.03.01 Strunz No: 05.AC.20
Locality:

Notes: