Blendes

(from German blenden, “to blind,” or “to deceive”), a group of minerals with a submetallic luster and other characteristics (color, density) inherent both to metal ores and minerals that are not metallic ores. The name was introduced in the Middle Ages by miners who often mistook these minerals for the ores of metals known in those times. The name has been retained for zinc blende (sphalerite), cadmium blende (CdS, or the mineral greenockite), sammetblende (fine-fibered aggregates of the mineral goethite), and other minerals. The blendes also include the mineral hornblende, the ferruginous varieties of which have a pronounced submetallic luster but are not an ore.