Amorphous Fluor Enlarge
May 1 1816
British Mineralogy
DXIII
Calx fluata

Amorphous Fluor

The purple specimen was lately sent me by my friend Mr. Samuel Wright of Cork, from near Tipperary in Ireland. A morn lions Fluate of Lime is not very common, and this variety is sufficiently remarkable to claim a place here, while we must not forget the Cornish Chlorophane* that has been particularly noticed by Mr. Phillips, who favoured me with specimens; one of them is represented in the lower figure, which, like the foreign ones, is united by Calcedony or Silex intimately mixed, so as to allow of ignition, or rather an exposure to a common red heat several times without cracking, when it gives a beautiful effulgence, or rich glow of a fine green or purple colour, &c. The purer crystallized fluor generally cracks just at the heat that best exhibits the colour, and flies to pieces. The Irish specimens may be heated two or three times, with care, but the flowing colour is not so vivid after the second time.

Our upper specimen fractures in somewhat irregular angles, and is interspersed with Carbonate of Lime, from which it is known partly by its lilac tinge and a lustre peculiar to Fluor in all its forms.

In the under specimen the Fluor is of a greyish colour mixed with Calcedony, and has brownish or ochracious Quartz interspersed in parts.

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