Amethyst scepter, small mineral from Chibuku in Zimbabwe.

Minerals are the hidden treasures of our planet—small wonders created by millions of years of geological processes. They are the building blocks of rocks and essential for countless applications, from jewellery to technological innovations. Some minerals are common, such as quartz and calcite, but others are extremely rare and valuable. Mineral rarity is affected by their chemical composition, formation conditions, and locations. Painite and grandidierite are rare minerals found in only a few places. Often, specific geological processes play a role in their formation, such as high pressure and temperature deep within the Earth’s crust. In addition to their scientific value, rare minerals are often coveted by collectors and jewellers. Gemstones such as diamonds, emeralds, and sapphires are sought after for their beauty and durability. But discovering a new, rare mineral remains an exciting event in the world of geology and mineralogy. The search for rare minerals continues today—from deep mines to meteorites falling to Earth from space. Each mineral tells a unique story about the history of our planet and the forces that shape it.