Comoros

Can almost every second grain of sand be green?

Near Pidjani on Grande Comore, some sand layers contain up to around 40 percent olivine.

That is unusual, ta sa the least. In ordinary sand, olivine is usually only a minor component. Here, it occurs in very high concentrations.

Olivine is an olive-green mineral that forms in volcanic rock. As the rock breaks down, the crystals are released and become grains of sand.