Muriate of Mercury, Corneous Mercury

The duchy of Deux Ponts, Bohemia, Hessla, and the mine Entredicho, in Spain, produce this ore of mercury. The present specimen is from Spain, and is in the cllection of the Royal Institution. It is rather confusedly crystallized in rectangular prisms, with obtuse four-sided pyramids variously modified. The crystals are always minute, and somewhat difficult to make out.

The muriate of mercury has rather a dull greasy aspect, and but moderate lustre, is but feebly transluscent, soft, and in the scratch there is not any perceptible change of colour; it can be cut with a knife easier than horn, and keeps together, being rather sectile; it volatilizes before a flame urged by the blow-pipe, emitting a garlick-like odour. Spec. Grav. no-where mentioned.

This specimen is from an old mine which was abandoned, no cinnabar having been found there; it is called Val de Azogue, i. e. Valley of Quicksilver, and lies one league distant to the east of Almadenejos.

The geometrical figure on the riglit-hand is copied from Haüy’s, and is, I believe, the simplest form known. The small faces upon the other figures, as far as I can judge by mere inspection, correspond with the faces of this.