sedimentary

Red Jasper or Carnelian (Agate)

Silicon Dioxide (SiO2)

AI-generated identification · may be incorrect

Hardness: 6.5-7 Mohs; Color: Deep reddish-brown; Luster: Vitreous to waxy; Crystal structure: Hexagonal (Microcrystalline/Cryptocrystalline); Conchoidal fracture.

Hardness: 6
Color: Deep reddish-brown
Luster: Vitreous to waxy

Identified July 10, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 Mohs; Color: Deep reddish-brown; Luster: Vitreous to waxy; Crystal structure: Hexagonal (Microcrystalline/Cryptocrystalline); Conchoidal fracture.

Formation & geological history

Formed through the accumulation of silica in groundwater within volcanic rock cavities or sedimentary layers. The reddish color is due to iron oxide (hematite) inclusions. Java, Indonesia, is rich in volcanic deposits that produce high-quality chalcedony and jasper.

Uses & applications

Commonly used as a gemstone (cabochons), in lapidary art, for jewelry making, and as a popular collector's item due to its polish and color.

Geological facts

In Indonesia, such stones are often referred to as 'Batu Akik'. Historically, red jasper was known as the 'warrior's stone' and was believed to provide protection and physical strength.

Field identification & locations

Identify by its hardness (cannot be scratched by a steel knife), smooth waxy feel when polished, and opacity or slight translucency at the edges. Very common in riverbeds across West and Central Java.