Ores and Minerals

Fascinating features of ores and minerals

Galena

Galena is the mineral of lead, chiefly of lead sulfide which is most abundant and widely distributed.
Galena is a semiconductor with a small bandgap of about 0.4 eV.

Uses

It was used in early wireless communication systems.
As the crystal in crystal radio sets, in which it was used as a point-contact diode to detect the radio signals.

Cinnabar

Cinnabar is generally found in a massive, granular or earthy form and is bright scarlet to brick-red in color, with rhombohedral bravais lattice.
Cinnabar resembles quartz in its symmetry and certain of its optical characteristics

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