Carbonate Group Visible Spectra (350 - 1100 nm)
The common colored carbonate minerals are calcite, CaCO3,
FeCO3, and rhodochrosite, MnCO3.
The color of calcite can be due to its iron content which is
as Fe2+, to Mn2+, to
radiation damage centers which
often involve rare-earth or other elements, or occasionally to other
such as Co2+ in what is commonly called cobaltian calcite.
owes its color to Fe2+
The color of
rhodochrosite is due to its Mn2+
minerals with Mn2+ in six-coordination are pale
Mn2+ does not absorb light strongly, a mineral
must have a high
Mn2+ concentration to be strongly colored by Mn2+.
Because some rhodochrosite specimens have a high degree of
light can penetrate deep into the crystal and be highly absorbed in the
Back to the list of minerals
Images of the spectra of representative carbonate minerals
ankerite, GRR 2808. Plotted as 1.0 mm thick.
Styria, Austria sample.
siderite, GRR 2810. Plotted as 1.0 mm thick.
mm thick sample; spectrum from a cleavage face polarized in the
of maximum pink color. Undisclosed Mexican locality. This variety of
is known as Terlingua-type calcite because of its pink color and strong
fluorescence under ultraviolet light. It is reported to contain the
earth element, europium. Data Files: a,
rhodochrosite, GRR 1858. 1.5 mm thick sample,
unpolarized spectrum from a cleavage face of a vibrantly red crystal.
Locality not specified, but probably Colorado. Data Files: a,
- Blue calcite, GRR
3008. 2.72 mm thick sample, unpolarized from a cleavage face.
Crestmore, Riverside County, California,
dolomite, GRR 3005. 0.378 mm thick sample, unpolarized from
a cleavage face. Union Company Reef, Maldon, Victoria, Australia.
Museum Victoria M1036.
- no other data files
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