Editing Diamond (section)

=== Exploration ===
[[File:Diavik Mine.tif|thumb|upright|[[Diavik Mine]], on an island in Lac de Gras in northern Canada]]

[[Kimberlite]] pipes can be difficult to find. They weather quickly (within a few years after exposure) and tend to have lower topographic relief than surrounding rock. If they are visible in outcrops, the diamonds are never visible because they are so rare. In any case, kimberlites are often covered with vegetation, sediments, soils, or lakes. In modern searches, [[geophysical survey|geophysical methods]] such as [[aeromagnetic survey]]s, [[electrical resistivity tomography|electrical resistivity]], and [[gravimetry]], help identify promising regions to explore. This is aided by isotopic dating and modeling of the geological history. Then surveyors must go to the area and collect samples, looking for kimberlite fragments or ''indicator minerals''. The latter have compositions that reflect the conditions where diamonds form, such as extreme melt depletion or high pressures in [[eclogite]]s. However, indicator minerals can be misleading; a better approach is [[geothermobarometry]], where the compositions of minerals are analyzed as if they were in equilibrium with mantle minerals.<ref name=Shirey2013/>

Finding kimberlites requires persistence, and only a small fraction contain diamonds that are commercially viable. The only major discoveries since about 1980 have been in Canada. Since existing mines have lifetimes of as little as 25 years, there could be a shortage of new natural diamonds in the future.<ref name=Shirey2013/>