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Calcite (CaCO3)

Calcite (CaCO3) Data Sheet     ♦ Calcite (CaCO3) MSDS

Calcite, or Iceland Spar, is a strongly birefringent material and is used for polarisers and retardation plates.

Transmission Range : 0.3 to 2.3 μm
Refractive Index : No 1.6654 at 0.51 μm
Reflection Loss : 11.7% at 0.51 μm (2 surfaces)
Absorption Coefficient : n/a
Reststrahlen Peak : n/a
dn/dT : 3 (para) 13 (perp) x 10-6 /°C at 0.5 micron
dn/dμ = 0 : n/a
Density : 2.71 g/cc
Melting Point : 825°C (Decomposes)
Thermal Conductivity : 5.526 (para) 4.646 (perp) W m-1 K-1 at 273K
Thermal Expansion : 25 (para) 5.8 (perp) x 10-6 /°C at 273K
Hardness : Knoop 155 Moh 3
Specific Heat Capacity : 852 J Kg-1 K-1
Dielectric Constant : 8 (para) 8.5 (perp) at 10kHz at 293K
Youngs Modulus (E) : 72.35 (perp) 88.19 (para) GPa
Shear Modulus (G) : 35 GPa
Bulk Modulus (K) : 129.53 GPa
Elastic Coefficients : C11=137; C12=45; C13=45; C14=(21); C33=79
Apparent Elastic Limit : 4.83 MPa (700 psi)
Poisson Ratio : n/a
Solubility : 0.0014g/100g water at 25°C
Molecular Weight : 100.09
Class/Structure : Trigonal (hex), R3c, {10-14} cleavage *see Product Notes

To download this data or our MSDS safety data sheet as a pdf, please click on the links at the top of the page.  To expand the transmission graphs, please click on the image.


µm   NoNeµm   NoNeµm   NoNe
0.20    1.9028 1.5765 0.30    1.7196 1.5137 0.41    1.6801 1.4954
0.51    1.6653 1.4896 0.64    1.6550 1.4849 0.71    1.6521 1.4835
0.80    1.6487 1.4822 0.91    1.6458 1.4810 1.04    1.6428 1.4799
1.50    1.6346 1.4774 1.91    1.627 1.4757 2.10    1.622 1.4749

Calcite is often mined naturally. Crystran Ltd has a stock of small calcite "rhombs" of good clear optical quality. Calcite cuts and polishes well.

CLEAVEAGE PLANE :
There can be confusion in the definition of the cleavage plane in calcite. Conventionally this has always been referred to as {10-11} but recent papers on AFM studies use {10-14}. Calcite cleaves between the bonds of the CO3 groups (in the CO3 layer). The CO3 group are offset relative  to each other and inclined to the c axis giving 3 cleavage directions defining a rhomb. Following the {10-11} nomenclature the unit cell requires ¼ the length of the c axis as measured from XRD (on a dimension 4 times longer). The correct Miller indices are {10-14} but the conventional {10-11} is often used in order not to confuse and for easier comparison. (1)

REFERENCES:
1. Private Communication. J.A.Elliott. Dept. Materials Science, University of Cambridge. 2011

WEBLINKS:
http://webmineral.com/data/Calcite.shtml - Has further information regarding Calcite.