Etymology, History, and Formation of Jasper
- The name 'jasper' means spotted or speckled stone and is derived from Old French and Latin.
- The word 'jasper' can be traced back in Arabic, Persian, Hebrew, Assyrian, Greek, and Latin.
- Green jasper was used to make bow drills in Mehrgarh between 4th and 5th millennium BC.
- Jasper was a favorite gem in the ancient world.
- Jasper forms through the deposition of silica-rich fluids in sedimentary environments.
- It is often found in association with volcanic rocks.
- The formation of jasper can take millions of years.
- Jasper can be found worldwide, with notable deposits in countries like Russia, Germany, and the United States.
Types and Colors of Jasper
- Jasper is an opaque rock of virtually any color.
- Patterns arise during the consolidation process forming flow and depositional patterns.
- Jasper can be modified by the diffusion of minerals along discontinuities.
- Weathering creates intensely colored superficial rinds.
- Jasper varieties are named after geographic localities, descriptive features, or places of origin.
- Common varieties include red jasper, picture jasper, and brecciated jasper.
- Jasper can exhibit a wide range of colors, including red, brown, yellow, green, and blue.
- The color of jasper is determined by the presence of impurities and mineral inclusions.
- Some varieties of jasper are highly sought after by collectors and gem enthusiasts.
Historical Significance and Uses of Jasper
- Jasper has been used for thousands of years for its aesthetic and symbolic value.
- It has been used in jewelry, decorative objects, and religious artifacts.
- Ancient civilizations believed that jasper had protective and healing properties.
- Jasper was highly valued in ancient Egypt and Greece.
- It is mentioned in various historical texts and religious scriptures.
- Jasper is widely used in jewelry making, including beads, pendants, and cabochons.
- It is also used for ornamental purposes, such as in vases, sculptures, and decorative tiles.
- Jasper has been used in traditional medicine for its believed healing properties.
- It is sometimes used as a material for carving and engraving.
- Jasper is valued for its aesthetic appeal and is often used as a focal point in design.
Banded Iron Formations and Picture Jaspers
- Jasper is the main component in the silica-rich parts of banded iron formations.
- Banded iron formations indicate low amounts of dissolved oxygen in the water.
- The red bands in banded iron formations are microcrystalline red chert, also called jasper.
- Picture jaspers exhibit combinations of patterns resulting in scenes or images.
- Patterns include banding, dendritic variations, and orbicular appearance.
- Specific colors or patterns of picture jaspers are unique to their geographic region of origin.
- Examples of picture jaspers include leopard skin jasper, liesegang jasper, and brecciated jasper.
- Ynys Llanddwyn in Wales is known for its picture jaspers.
Basanite and Other Types of Touchstone
- Basanite is a deep velvety-black variety of amorphous quartz.
- Basanite was the touchstone of the ancients and used to test the purity of precious metal alloys.
- Basanite, Lydian stone, and radiolarite are terms used to refer to several types of black, jasper-like rock.
- These rocks are dense, fine-grained, and flinty/cherty in texture.
- Different rock types have been used as touchstones, leading to confusion in this field of study.
Jasper Data Sources