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2. Greywacke - Wikipedia

   en.wikipedia.org/wiki/Greywacke

   Greywacke or graywacke (German grauwacke, signifying a grey, earthy rock) is a variety of sandstone generally characterized by its hardness (6–7 on Mohs scale), dark color, and poorly sorted angular grains of quartz, feldspar, and small rock fragments or sand-size lithic fragments set in a compact, clay -fine matrix.

3. Quartz - Wikipedia

   en.wikipedia.org/wiki/Quartz

   Quartz. Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO 4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of SiO 2. Quartz is, therefore, classified structurally as a framework silicate mineral ...

4. Carrara marble - Wikipedia

   en.wikipedia.org/wiki/Carrara_marble

   Carrara marble, or Luna marble (marmor lunense) to the Romans, is a type of white or blue-grey marble popular for use in sculpture and building decor. It has been quarried since Roman times in the mountains just outside the city of Carrara in the province of Massa and Carrara in the Lunigiana, the northernmost tip of modern-day Tuscany, Italy.

5. List of types of marble - Wikipedia

   en.wikipedia.org/wiki/List_of_types_of_marble

   Daleti marble, Western Welega: white, white with grey veins and other colours [1] Enda Tikurir marble, Western Tigray. Newi marble, Central Tigray. Akmara marble, Central Tigray. Dichinamo marble, Western Tigray.

6. Prasiolite - Wikipedia

   en.wikipedia.org/wiki/Prasiolite

   Prasiolite. Prasiolite (also known as green quartz, green amethyst or vermarine) is a green variety of quartz. Since 1950, almost all natural prasiolite has come from a small Brazilian mine, [citation needed] but it has also been mined in the Lower Silesia region of Poland. Naturally occurring prasiolite has also been found in the Thunder Bay ...

7. Quartz-porphyry - Wikipedia

   en.wikipedia.org/wiki/Quartz-porphyry

   Quartz porphyry from the island of Alnö, Sweden. Phenocrysts of clear glassy rounded quartz and white orthoclase feldspar are set in a fine-grained matrix. Sample is just over 10 cm long. Quartz-porphyry, in layman's terms, is a type of volcanic (igneous) rock containing large porphyritic crystals of quartz. [1][2] These rocks are classified ...

8. Tintype - Wikipedia

   en.wikipedia.org/wiki/Tintype

   Tintype. A tintype, also known as a melanotype or ferrotype, is a photograph made by creating a direct positive on a thin sheet of metal, colloquially called 'tin' (though not actually tin-coated), coated with a dark lacquer or enamel and used as the support for the photographic emulsion.

9. Egyptian faience - Wikipedia

   en.wikipedia.org/wiki/Egyptian_faience

   Egyptian faience is a non-clay based ceramic composed of crushed quartz or sand, with small amounts of calcite lime and a mixture of alkalis, displaying surface vitrification due to the soda lime silica glaze often containing copper pigments to create a bright blue-green luster. [7]