Heazlewoodite, millerite and nickel arsenide. Unst. Shetland Islands, Britain
Small crystals of nickel arsenide (pink-brown, top right, centre left) are included within heazlewoodite (cream-white, centre) which is the main phase. Heazlewoodite shows multiple twinning along (0221) (bottom left) and alteration to lower reflectance, yellow millerite (bottom right) along a north-south oriented fracture. Black areas are silicates.
Polished thin section, plane polarized light, x 160, oil