Jasper

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