Jasper

Physical Properties

Hardness: 6.5-7 (Mohs scale); Color: Yellow-brown, tan, ochre, with greyish veining; Luster: Vitreous to waxy; Structure: Microcrystalline; Cleavage: None; Fracture: Conchoidal; Specific Gravity: 2.6-2.9.

Formation & Geological History

Formed through the accumulation of fine silica from groundwater in sedimentary environments, often replacing volcanic ash or organic matter over millions of years. This piece shows signs of stream-tumbling (rounded edges).

Uses & Applications

Popular for lapidary work, decorative cabochons, jewelry, stone carving, and as a collector's specimen. It is also used in tumble-polishing.

Geological Facts

Jasper is colored by impurities, most often iron oxides which provide the yellow and brown hues. The thin dark lines in this specimen are secondary mineral 'veins' that filled cracks in the stone as it formed.

Field Identification & Locations

Identify in the field by its smoothness, lack of visible grain, and hardness (it will scratch glass). Commonly found in riverbeds, glacial tills, and desert pavements globally.

Identified on: 4/15/2026

Mode: Standard