mineral
Carnelian Agate
Silicon Dioxide (SiO2) - Variety of Chalcedony
AI-generated identification · may be incorrectHardness: 6.5-7 on Mohs scale. Color: Reddish-brown to orange-red. Luster: Waxy to vitreous. Crystal Structure: Hexagonal (cryptocrystalline). Cleavage: None, exhibits conchoidal fracture. Specific Gravity: 2.58-2.64.
- Hardness
- 6
- Color
- Reddish-brown to orange-red
- Luster
- Waxy to vitreous
Identified More mineral →
Explore Carnelian Agate in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6.5-7 on Mohs scale. Color: Reddish-brown to orange-red. Luster: Waxy to vitreous. Crystal Structure: Hexagonal (cryptocrystalline). Cleavage: None, exhibits conchoidal fracture. Specific Gravity: 2.58-2.64.
Formation & geological history
Formed in the cavities of volcanic rocks (basalt or rhyolite) through the deposition of silica from groundwater. The red color is due to the presence of iron oxide (hematite) impurities. Often found in riverbeds and beaches as water-worn pebbles.
Uses & applications
Commonly used as a gemstone in jewelry (beads, cabochons), for ornamental carvings, seals, and as a popular collector's specimen.
Geological facts
Carnelian was used by ancient Egyptians and Romans for signet rings and amulets. It was believed to provide courage and protection for the soul in the afterlife. The depth of color is often enhanced by natural solar heat or artificial heating.
Field identification & locations
Identify in the field by its translucent quality, waxy feel, and reddish-orange hue. Its conchoidal fracture (curved, glass-like breaks) is a key identifier. Commonly found in Brazil, India, Uruguay, and parts of the United States.
