1. Quartz by-nc: Travis S. by-nc-nd: Orbital Joe

2. With few exceptions, most early stone tools were fashioned of quartz. by: Yandle by-nc-nd: Western Sahara Project by-nc-sa: mharrsch by-nc-sa: keepps

3. by-nc-nd: xrichx by-nc-sa: Ron Schott by-nc-sa: Monceau Quartz is in igneous and metamorphic rocks. by-nc-sa: Ron Schott by-nc: smiling_da_vinci

4. by: fatal Cleopatra by-nc-nd: Phil Romans Quartz is in the sediments sand and silt, by-nc-nd: Jason Abbott

5. by-sa: Shital Shah the sedimentary rocks sandstone and siltstone, by-nc: Simonds

6. by: cogdogblog as well as their metamorphosed equivalents of quartzite and slate. by-nc-sa: dewo

7. ‘Chert’ is a term collectively used for all the quartz varieties that have crystals too small to be seen without a microscope. Chert color varieties are: onyx (mixed white and black), here with rose quartz flint (gray to black) by-nc-sa: Wessex Archaeolog jasper (red to red- brown) by-nc-nd: Narisa by-nc-nd: Helmetti

8. Chert precipitated from silica-rich groundwater can replace bone and wood present in sediment and sedimentary rocks by-nc: Terrie Weng by-nc: Ottoman42 by-nc: chrissam42

9. rose quartz by-nc-nd: oldbones opal: rough and polished by-nc-nd: Helmetti chalcedony by-nc-nd: oldbones by: jaja_1985 by-nc-nd: Future-PhD. by-nc-nd: Orbital Joe by-nc-sa: jspace3 Quartz by other names: amethyst agate citrine tiger’s eye

10. When chert is struck against iron, it produces a relatively long-lived spark. by: westy559 Historically, the single most important use of quartz may have been to start fires. by-sa: matthewvenn

11. Quartz is in building stones. by-nc-sa: Ben McLeod by-nc-sa: mharrsch by-nc-sa: rowlock by-nd: mike.wilson

12. Quartz is mixed with clay and ground-up feldspar, and then fired to form a wide range of ceramic and porcelain products. by-sa: Ebua Libana by-nc: birdfarm by-nc-sa: amortize by-nc: bombelek

13. Quartz is used in the manufacture of glass by-nd: savinca by-nc-sa: dachalan by-nc-nd: gsgeorge by-sa: bongo vongo by-nc-sa: Rob Ireton

14. Quartz is often in concrete and asphalt as aggregate and sand. by-nc-nd: Orbital Joe by-nc-sa: portfolium by-sa: crouchingbadger by-nc-sa: PPDIGITAL

15. Quartz is used as a flux for metallurgy. A flux is a material that melts easily and can be used to remove impurities from metal ores, or that makes the slag produced by metal ore smelting more fluid. by-sa: Southern_Comfort by-nc-sa: BBColin

16. Many species of marine plankton, called diatoms, construct their shells of quartz. As these microscopic organisms die, they sink down to cover the deep sea floor with layers of porous diatom shells. USGS by-nc-sa: Adrian Barnes by-nc-sa: Leo Reynolds Diatomaceous earth is the abrasive part of toothpaste. Since it is composed of quartz, the shells are harder than the apatite and calcite minerals that make up our teeth. When you polish your teeth, you actually are grinding the surface down with a very fine abrasive, often the shells of long dead plankton. Ancient deep sea diatom deposits now exposed at the Earth’s surface are called diatomaceous earth.

17. Quartz is the abrasive in stonecutting, sandblasting, and scouring soaps by-nc-sa: Merrick Brown by-nc-nd: CheriGaulke by-nc-nd: lobstar28

18. by-nc-nd: jwinfred Pure quartz crystals are piezoelectric – that means that when put under pressure, the crystal produces an electric voltage. by-sa: threedots This characteristic allows quartz crystals to be used to measure pressures or control the frequency of electric impulses, which led to their use in radio systems and timepieces.

19. Quartz can be a host rocks for gold and other precious metals. by-nc-nd: Mundoo by-nc: Ifn by: RickC

20. Quartz by-nc: Travis S. by-nc-nd: Orbital Joe

21. media rights Many of the photos in this presentation were obtained through Flickr and Wikipedia.FlickrWikipedia Funded by FIPSE and by the University of Minnesota. Compiled for Dr. Kent Kirkby, Department of Geology and Geophysics, by Kate Rosok, 2007. Each displayed image retains its original media rights. For educational purposes only; not to be used commercially.FIPSEUniversity of MinnesotaDr. Kent Kirkby Department of Geology and Geophysics public domain (none) © Copyright. All rights reserved by-nc-sa by by-nd by-sa by-nc-nd Creative Commons Licenses GNUGNU GNU Free Documentation LicenseGNU Free Documentation License Our notation description