What is ruby silver; dark red silver ore. It is a sulphide of antimony and silver, occurring in rhombohedral crystals or massive, and is of a dark red or black color with a metallic adamantine luster called?

pyrargyrite — Ruby silver; dark red silver ore. It is a sulphide of antimony and silver, occurring in rhombohedral crystals or massive, and is of a dark red or black color with a metallic adamantine luster. (Webster's 1913.)

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