IntroductionJasper is derived from the Greek for "spotted stone". Jasper is usually considered a chalcedony, but put by scientists in a group by itself because of its grainy structure. The finely grained, dense jasper contains up to twenty percent foreign materials that determine its color, streak and appearance. Uniform jasper is rare. It usually is multicolored, striped spotted or flamed. Some of the most treasured gems are those that show a picture that appears to be taken from nature, called "landscapes". Oregon's Biggs Jasper is now the most common source. Another specialty is bloodstone or blood jasper, also known as "heliotrope", a dark green chalcedony or jasper with flecks of red. Bloodstone is the Zodiac birthstone for Aries. Jasper colorsJasper comes in all colors, mostly striped, spotted or flamed. A variety of trade names specify colors, appearance or composition.Agate jasper: Yellow, brown or green blended, grown together with agate Egyptian jasper: Strongly yellow and red Banded jasper: Layered structure with more or less wide bands Basanite: Fine-grained black Blood jasper: Bloodstone, dark green with flecks of red Hornstone: Very fine grained, gray, brown-red, more rarely green or black Scenic jasper: Brown marking caused by iron oxide, resembling a landscape. Oregon's "Biggs Jasper" is now the most common source. "Bruneau Jasper", from Bruneau Canyon, Idaho, is praised for its blue "skies". Moukaite: Pink to light red, cloudy Plasma: Dark green, sometimes with white or yellow spots Silex: Yellow and brown-red spotted or striped Buying JasperColorThere is no recommendation for color. The saturation of the color defines the value. The choice will more often depend on taste for the appearance and composition of the stone. Clarity Most jasper is opaque and takes an excellent polish. Cut Jasper is used for ornamental objects, cabochons and stone mosaics. Care must be taken during cutting. Banded jasper tends to separate along the layers. Jasper location and depositsJasper is found in Australia, Brazil, Canada, Egypt, India, Indonesia, Kazakhstan, Madagascar, Russia, Uruguay and the United States.Common Jasper treatments Occasionally dyed. World-famous Jasper Jasper didn't make it yet into the hall of fame for gemstones. Jasper gemologySpecies: ChalcedonyColor: All colors, mostly striped or spotted Chemical composition: SiO2 silicon dioxide Crystal system: (Trigonal) microcrystalline aggregate Hardness: 6.5 - 7 (Mohs scale) Specific gravity: 2.58 - 2.91 Refractive index: About 1.54 Birefringence: None Color of streak: White, yellow, brown, red Absorption spectrum: Cannot be evaluated Fluorescence: None The Jasper zodiac, myth & legendThe name bloodstone, as it indicates, goes back to ancient Christianity, believing that Jesus Christ's blood dripped from the cross onto a dark green stone that lay beneath it.Bloodstone is the Zodiac stone for Aries. In Antiquity, as well as in the Middle Ages people believed that the cosmos is reflected in gemstones. The bloodstone is assigned to the planets Mars and Pluto. The esoteric movement revived the ancient belief and the gem industry made it another marketing tool to promote certain gems. The healing powers of gems remain a controversial issue, but are mentioned for centuries by healers, shamans and medicine men. Whether it's a fact or a placebo effect doesn't matter, if it helps. The safest approach is to wear the gemstone in skin contact to the troubled part of the body. Jasper is said to be of help for pancreas, sciatica and troubled toenails. First Published: October-09-2006 © 2003-2008 GemSelect.com all rights reserved. Reproduction (text or graphics) without the express written consent of GemSelect.com (SETT Company Ltd.) is strictly prohibited. |
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