As highlighted in the photos

although it can also occur in shades of green

Molybdenite

This beautiful cluster combines tetrahedrite and calcite crystals

Amethyst can occur in different variations

Skutterudite Crystal | 692 grams | Bou Azzer, Morocco Rutilite As highlighted in the photosSharp lustrous metallic crystals makes this top specimen of Skutterudite most beautiful and unique. Some pearly white Calcite is intergrown between crystals. Although most Skutterdite are uninteresting in form, several localities have produced sharp, lustrous crystals that are striking in aesthetics like this one. The Bou Azer District, Morocco, produces the best examples of Skutterudite, in large, lustrous crystals, often in a cuboctadral shape.