sedimentary

Yellow Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Hardness: 6.5-7 (Mohs scale); Color: Yellow to brownish-gold; Luster: Dull or waxy when unpolished; Crystal structure: Microcrystalline (trigonal); Cleavage: None (conchoidal fracture); Specific gravity: 2.6-2.7

Hardness: 6
Color: Yellow to brownish-gold
Luster: Dull or waxy when unpolished

Identified March 18, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the deposition of silica from volcanic ash or water-borne sources into porous rocks or clay. Over millions of years, heat and pressure solidify the mixture into microcrystalline quartz, with iron oxides providing the yellow coloration.

Uses & applications

Commonly used in jewelry (cabochons and beads), decorative ornaments, stone carvings, and lapidary tumbling for hobbyists.

Geological facts

Jasper has been used as a gemstone since antiquity; the name is derived from the Greek word 'iaspis', meaning 'spotted stone'. It is an opaque variety of chalcedony and has been used in spiritual traditions for grounding and protection.

Field identification & locations

Identify in the field by its opaque nature (unlike agate, light will not pass through it), smooth waxy feel, and its ability to scratch glass. Found globally in riverbeds and areas with ancient volcanic activity.

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