Diopside is a calcium magnesium silicate with a hardness of 5.5-6. It may form in short prismatic crystals or in granular or massive habits. Its colour is usually in shades of light/dark green or green/black. Sometimes it displays asterism (4-rayed) and is known as Star Diopside. Occasionally it may be white/clear or white/blue (Violan).
How Diopside is best used depends on its colour, although all forms help us connect more closely with the Earth. Green (Chromium) Diopside is very clearing, balancing and generally healing. The deep green variety is said to be a profound stone for connecting one's own heart to the heart of the Earth, facilitating communication with all manifestations of her consciousness. Black Diopside is strongly grounding, providing a firmer connection to the Earth Star chakra, enabling excess energy to be grounded and planetary energies to be more easily utilised. It is also a wonderful stone for the geomancer to work with. Star Diopsides all have enhanced energies, permitting profound connections to be made between Earth and the Cosmos.