Jasper 75355 225301540 2008-07-12T23:48:50Z WadeSimMiser 170099 Reverted edits by [[Special:Contributions/69.230.218.40|69.230.218.40]] to last version by Vsmith (using [[WP:HG|Huggle]]) :''This article is about the mineral. For other uses see [[Jasper (disambiguation)]]'' [[Image:jasper.pebble.600pix.bkg.jpg|thumb|180px|Polished jasper pebble, one inch (2.5 cm) long.]] [[Image:unpolished jasper.jpg|thumb|180px|Jasper that has not been polished.]] [[Image:Jaspis orbikularny Madagaskar.jpg|thumb|180px|Green Jasper.]] [[Image:Jaspis pejzażowy.jpg|thumb|180px|Yellow Jasper. Can also be brighter and less brown.]] '''Jasper''' is an [[Opacity (optics)|opaque]],<ref>[http://www.mindat.org/min-2082.html Mindat: Jasper profile]</ref> impure variety of [[silica]], usually [[red]], [[yellow]] or [[brown]] in color. This [[mineral]] breaks with a smooth surface, and is used for ornamentation or as a [[gemstone]]. It can be highly polished and is used for vases, seals, and at one time for [[tobacco|snuff]] boxes. When the colors are in stripes or bands, it is called ''striped'' or ''banded'' jasper. Jaspilite is a [[banded iron formation]] rock that often has distinctive bands of jasper. Jasper is basically [[chert]] which owes its red color to iron(III) inclusions. The [[specific gravity]] of jasper is typically 2.5 to 2.9.<ref>[http://www.cst.cmich.edu/users/dietr1rv/jasper.htm R. V. Dietrich, ''Gemrocks'']</ref> ==Etymology and history== The name means "spotted stone", and is derived from [[Anglo-French]] ''jaspre'', from [[Old French]] ''jaspe'', from [[Latin]] ''iaspidem'', the accusative of ''iaspis'', from [[Greek language|Greek]] ''iaspis'', via a [[Semitic]] language (cf. [[Hebrew language|Hebrew]] ''yashepheh'', [[Akkadian language|Akkadian]] ''yashupu''), ultimately from [[Persian language|Persian]] ''yashp''. Jasper is known to have been a favourite gem in the ancient world; its name can be traced back in [[Hebrew]], [[Assyria]]n, [[Persia]]n, Greek and Latin.<ref>[*http://www.gemstone.org/gem-by-gem/english/jasper.html International Colored Gemstoen Association: Jasper]</ref> On [[Minoan]] [[Crete]] within present day [[Greece]] jasper was carved to produce seals circa 1800 [[BC]] based upon archaoelogical recoveries at the [[palace]] of [[Knossos]].<ref>[http://letmespeaktothedriver.com/site/10854/knossos.html#fieldnotes C. Michael Hogan, ''Knossos fieldnotes'', Modern Antiquarian (2007)]</ref> The word ''yashepheh'' in the [[Masoretic text]] of [[Exodus]] 28:20, referring to a stone in the [[Hoshen]], is thus reflected in the [[Septuagint]] by the word ''Iaspis'', and usually translated into English as ''Jasper''. Despite the most common form of Jasper being red, scholars think that the ''yashepheh'' here actually refers to a green form of Jasper - which was very rare, and so highly prized; the Greeks used ''Iaspis'' to refer to the green form, while the red form simply fell under the term ''Sard'' - which just means ''red''. [[Bahya ben Asher|Rebbenu Bachya]] argues that this stone represents the tribe of [[Benjamin]], but there is actually a wide range of views among traditional sources about which tribe the stone refers to. It is described in the [[Book of Revelation]] (21:11) as follows: "It shone with the glory of God, and its brilliance was like that of a very precious jewel, like a jasper, clear as crystal." ==Types of jasper== Jasper can appear as an opaque rock of shades of red due to mineral impurities. Patterns can arise from the formation process and from flow patterns in the [[sediment]] or [[volcanic ash]] that was saturated with silica to form jasper, yielding bands or swirls in the rock. Jasper may be permeated by [[Dendrite (crystal)|dendritic]] minerals providing the appearance of vegetative growths. The jasper may have been fractured and/or distorted after formation, later rebonding into discontinuous patterns or filling with another material. Heat or environmental factors may have created surface rinds (such as varnish) or interior stresses leading to fracturing. A brown jasper that occurs as nodules in the Libyan desert and in the Nile valley is known as Egyptian jasper or Egyptian pebble. Picture jaspers simultaneously exhibit several of these variations (such as banding, flow patterns, dendrites or color variations) resulting in what appear to be scenes or images in a cut section. Spherical flow patterns produce a distinctive orbicular appearance. Complex mixes of impurities produce color variations. Healed fractures produce [[Breccia|brecciated]] jasper. Examples of this can be seen at [[Llanddwyn Island]]. [[Orbicular jasper]] or ''leopard jasper'' is usually an opaque combination of tan, gray, black or reddish-brown circles or 'spots' of color, hence its name. ==See also== {{Commonscat|Jasper}} * [[Carnelian]] * [[Sard]] ==References== {{reflist}} {{Jewellery Materials}} {{Silica minerals}} [[Category:Quartz varieties]] [[az:Yəşəm]] [[cs:Jaspis]] [[de:Jaspis]] [[es:Jaspe]] [[eo:Jaspo]] [[fr:Jaspe]] [[it:Diaspro]] [[he:ישפה]] [[la:Iaspis]] [[lv:Jašma]] [[lt:Jaspis]] [[nah:Tecpacuihcuilli]] [[nl:Jaspis]] [[ja:碧玉]] [[pl:Jaspis]] [[pt:Jaspe]] [[ro:Jasp]] [[ru:Яшма]] [[sk:Jaspis]] [[sv:Jaspis]] [[zh:賈斯珀]]