What is Diopside?
Diopside is a calcium-magnesium pyroxene found in igneous rocks, marbles and contact-metamorphic skarns.
Mineralogy and structure
The reference formula is CaMgSi2O6. Diopside is classified with the silicates and its crystal system is monoclinic. Natural specimens can vary in composition, habit and degree of crystallinity, so the locality and observed form remain important.
Colour and appearance
Typical colours include green, pale yellow, brown, grey and colourless. Lustre, transparency, inclusions and surface condition should be described for the individual specimen rather than inferred from the name alone.
Formation and localities
Diopside forms in or is associated with mafic and ultramafic rocks, marbles and skarns. Notable collecting regions include Italy, Russia, Pakistan, Canada, Madagascar and the United States. A precise locality is more useful than a broad country label when it is documented.
Collecting notes
Diopside is useful in a reference collection because its appearance connects mineral chemistry with geological setting. Store specimens dry, protected from impact and clearly labelled with the confirmed material, locality and any treatment history.
