Projekt: Bestände der Universitätsbibliothek Freiberg
LDP: UB Freiberg Druckschriften
Strukturtyp
Band
Parlamentsperiode
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Wahlperiode
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Titel
Essay, Of A Method for examining Minerals
Untertitel
By which we may be enabled to ascertain the distinguishing characters, and principal prevalent component parts, of a mineral substance; and to determine thereby, the class, division, order, genus, and species, to which it may accordingly belong, and be placed in the systematical arrangement, which I have adopted. This method will be found applicable by those who are acquainted with the rudiments of chemistry
examining Mineral's. 3 11 Sect. 4. 1 They are femitranfparent in different de grees—they do not fufe per fe in the heat which thofe of the third fedtion fufe in—moft of them ftrike fire with fteel. They are not, or at leaft very little adted upon bv acids. They have a cloudy or milky appearance. They exhibit, no perfedt cryftallifation, or regular fhape, or at leaft leldom— they are all lefs hard than rock cryftal—they are not opalefcent, or do not refledt light in different colours, c. g. Calcedohy Flint — Cornelion — Cryfoprajs — Solid Amorphous Quartz, and Shade. Sect. 5. They are opalefcent, or refledt different co lours on account of their peculiar texture j they are only femitranfparent; they do not ftrike fire with fteel, and their furface can be fcratched by rock-cryftal and calcedony. They become opaque in fire, and are a little adted X 4 upon