Micromount Club Zoom meeting video

Mineral Matters #457

This month’s Micromount Club Zoom meeting presentation was Polymorphs, presented by Frank Loman.

In mineralogy, polymorphs are minerals that share the same chemical composition but have different crystal structures. This phenomenon occurs because the atoms in a mineral can arrange themselves in different ways depending on factors like temperature and pressure during formation. For example, the mineral carbon can form both diamond and graphite. Despite having the same chemical composition (pure carbon), diamond has a cubic crystal structure, while graphite has a hexagonal structure. Another example is calcium carbonate (CaCO₃), which can form both calcite and aragonite.

Frank explains this very well and illustrates the phenomenon using a number of different mineral species.

You can watch the video here.