Heazlewoodite, millerite and nickel arsenide. Unst, Shetland Islands, Britain
125µm
This is the same field of view as previous section but with partially crossed polars. The strong anisotropy of heazlewoodite (blush-pink and blue-grey) and extreme anisotropy of millerite (golden yellow to deep blue) are visible. Millerite forms along the fractures in heazlewoodite but is associated with a phase with less intense anisotropy colours (orange-brown, left centre to blue-grey, centre right) which has the optical properties of godlevskite. Blue-green internal reflections of serpentine arc striking.
Polished thin section, partially crossed polars, x 160, oil
