Chalcopyrite from Indonesia's Tasik region has a brass yellow color with an iridescent tarnish showing green, blue, or purple hues. Named from Greek 'chalkos' and 'pyrites' for 'copper' and 'striking fire'. Softer than pyrite, it scratches with a nail. Acid treatment displays entire rainbow, with purple and blue most common. The natural tarnish is less vibrant but still beautiful. This specimen has not been acid treated, weighing 1.11 lbs and measuring 3"x3"X2". It combines the beauty of chalcopyrite's colors with the miniature cubes of pyrite.
