Editing Calcite (section)

=== Thermoluminescence ===
Calcite has [[Thermoluminescence|thermoluminescent]] properties mainly due to manganese divalent ({{chem2|Mn(2+)}}).<ref name="Medlin">{{cite journal |last1=Medlin |first1=W. L. |title=Thermoluminescent properties of calcite. |journal=The Journal of Chemical Physics |date=1959 |volume=30 |issue=2 |pages=451–458 |doi=10.1063/1.1729973 |bibcode=1959JChPh..30..451M}}</ref> An experiment was conducted by adding activators such as ions of Mn, Fe, Co, Ni, Cu, Zn, Ag, Pb, and Bi to the calcite samples to observe whether they emitted heat or light. The results showed that adding ions ({{chem2|Cu+}}, {{chem2|Cu(2+)}}, {{chem2|Zn(2+)}}, {{chem2|Ag+}}, {{chem2|Bi(3+)}}, {{chem2|Fe(2+)}}, {{chem2|Fe(3+)}}, {{chem2|Co(2+)}}, {{chem2|Ni(2+)}}) did not react.<ref name="Medlin" />  However, a reaction occurred when both manganese and lead ions were present in calcite.<ref name="Medlin" />  By changing the temperature and observing the glow curve peaks, it was found that {{chem2|Pb(2+) }}and {{chem2|Mn(2+)}}acted as activators in the calcite lattice, but {{chem2|Pb(2+)}} was much less efficient than {{chem2|Mn(2+)}}.<ref name="Medlin" />

Measuring mineral thermoluminescence experiments usually use x-rays or gamma-rays to activate the sample and record the changes in glowing curves at a temperature of 700–7500&nbsp;K.<ref name="Medlin" /> Mineral thermoluminescence can form various glow curves of crystals under different conditions, such as temperature changes, because impurity ions or other crystal defects present in minerals supply luminescence centers and trapping levels.<ref name="Medlin" /> Observing these curve changes also can help infer geological correlation and age determination.<ref name="Medlin" />