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Magnetic pyrites, copper pyrites, zinc blende and arsenical pyrites are other and less important examples, the last constituting the gold ore formerly worked in Silesia.

For instance, common iron pyrites, FeS2, is unresponsive, whilst the magnetic pyrites, which varies from 5FeS, Fe2S3, to 6FeS, Fe2S3, and is a sulphide of iron, is responsive both positively and negatively.