Emery, or corundite, is a dark granular rock used to make an abrasive powder. It largely consists of corundum (aluminium oxide), mixed with other minerals such as the iron-bearing spinels, hercynite, and magnetite, and also rutile (titania). Industrial emery may contain a variety of other minerals and synthetic compounds such as magnesia, mullite, and silica.
Corundite from the Naxos emery deposits. The corundum is blue, or sapphire. Wet slab, 10 cm (3.9 in) wide.
It is black or dark grey in colour, less dense than translucent-brown corundum with a specific gravity of between 3.5 and 3.8. Because it can be a mixture of minerals, no definite Mohs hardness can be assigned: the hardness of corundum is 9 and that of some spinel-group minerals is near 8, but the hardness of others such as magnetite is near 6.
Crushed or naturally eroded emery (known as black sand) is used as an abrasive—for example, on emery boards and emery cloth. It is also used as a traction enhancer in asphalt and tarmac mixtures.
Turkey and Greece are the main suppliers of the world's emery. These two countries produced about 17,500 tons of the mineral in 1987.[1]
The Greek island of Naxos used to be the main source of this industrially important rock type. It has been mined on the eastern side of Naxos for well over two thousand years as mentioned by Pliny the Elder's The Natural History, BOOK XXXVII, CHAP. 32. However, demand for emery has decreased with the development of sintered carbide and oxide materials as abrasives.
A small quantity of emery is used in coated abrasive products, but its main use in the United States is wear-resistant floors and pavements.[2] Many tons are shipped to Asia to be used in grinding rice.[3]
In the United States, the Occupational Safety and Health Administration has set permissible exposure limits for emery in the workplace: TWA 15 mg/m3 total exposure and TWA 5 mg/m3 respiratory exposure.[4]
Oberg, Erik; Jones, Franklin D.; Horton, Holbrook L.; Ryffel, Henry H. (2000). Machinery's Handbook (26th ed.). New York: Industrial Press Inc. ISBN0-8311-2635-3.
Wikimedia Commons has media related to Emery (rock).
CDC - NIOSH Pocket Guide to Chemical Hazards
Emery mining in Waldthurn
February 05, 2023
emery, rock, this, article, needs, additional, citations, verification, please, help, improve, this, article, adding, citations, reliable, sources, unsourced, material, challenged, removed, find, sources, emery, rock, news, newspapers, books, scholar, jstor, a. This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Emery rock news newspapers books scholar JSTOR April 2010 Learn how and when to remove this template message Emery or corundite is a dark granular rock used to make an abrasive powder It largely consists of corundum aluminium oxide mixed with other minerals such as the iron bearing spinels hercynite and magnetite and also rutile titania Industrial emery may contain a variety of other minerals and synthetic compounds such as magnesia mullite and silica Emery mine on Naxos Island Corundite from the Naxos emery deposits The corundum is blue or sapphire Wet slab 10 cm 3 9 in wide It is black or dark grey in colour less dense than translucent brown corundum with a specific gravity of between 3 5 and 3 8 Because it can be a mixture of minerals no definite Mohs hardness can be assigned the hardness of corundum is 9 and that of some spinel group minerals is near 8 but the hardness of others such as magnetite is near 6 Crushed or naturally eroded emery known as black sand is used as an abrasive for example on emery boards and emery cloth It is also used as a traction enhancer in asphalt and tarmac mixtures Turkey and Greece are the main suppliers of the world s emery These two countries produced about 17 500 tons of the mineral in 1987 1 The Greek island of Naxos used to be the main source of this industrially important rock type It has been mined on the eastern side of Naxos for well over two thousand years as mentioned by Pliny the Elder s The Natural History BOOK XXXVII CHAP 32 However demand for emery has decreased with the development of sintered carbide and oxide materials as abrasives A small quantity of emery is used in coated abrasive products but its main use in the United States is wear resistant floors and pavements 2 Many tons are shipped to Asia to be used in grinding rice 3 In the United States the Occupational Safety and Health Administration has set permissible exposure limits for emery in the workplace TWA 15 mg m3 total exposure and TWA 5 mg m3 respiratory exposure 4 Contents 1 See also 2 References 3 Further reading 4 External linksSee also EditEmery paperReferences Edit G T Austin 1987 Minerals Yearbook Volume 1 pp 71 84 Jacqueline Kroschwitz 2004 Kirk Othmer encyclopedia of chemical technology 5th ed Hoboken NJ Wiley Interscience p 10 ISBN 9780471484943 P Harbin November 1978 Industrial Minerals Metal Bulletin 49 73 a href Template Cite journal html title Template Cite journal cite journal a Missing or empty title help NIOSH Pocket Guide to Chemical Hazards 0250 National Institute for Occupational Safety and Health NIOSH Further reading EditOberg Erik Jones Franklin D Horton Holbrook L Ryffel Henry H 2000 Machinery s Handbook 26th ed New York Industrial Press Inc ISBN 0 8311 2635 3 External links Edit Wikisource has the text of the 1879 American Cyclopaedia article Emery Wikimedia Commons has media related to Emery rock CDC NIOSH Pocket Guide to Chemical Hazards Emery mining in Waldthurn Retrieved from https en wikipedia org w index php title Emery rock amp oldid 1133293703, wikipedia, wiki, book, books, library,
