gemstone

Yellow Agate

Silicon Dioxide (Chalcedony variety), SiO2

Hardness: 6.5 to 7 on the Mohs scale. Color: Shades of yellow, orange, white, and translucent amber. Luster: Waxy to vitreous. Crystal Structure: Trigonal (microcrystalline/cryptocrystalline quartz). Cleavage: None, exhibits conchoidal fracture. Specific Gravity: 2.58 to 2.64.

Hardness: 6
Color: Shades of yellow, orange, white, and translucent amber
Luster: Waxy to vitreous

Identified August 1, 2026More gemstone →

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Physical properties

Formation & geological history

Forms primarily in the cavities of volcanic rocks or ancient lavas through the slow deposition of silica-rich groundwater solutions over millions of years. Geological age varies widely depending on the deposit, ranging from Precambrian to recent volcanic eras.

Uses & applications

Used frequently in jewelry, ornamental carvings, polished display specimens, and metaphysical crystal collections.

Geological facts

Agates are known for their banded patterns caused by alternating layers of solutions, though some varieties like this exhibit blocky or heavily stained chalcedony formations. Ancient civilizations valued agates for talismans and amulets.

Field identification & locations

Can be identified in the field by its waxy luster, conchoidal fracture, and high hardness which easily scratches glass. Commonly found in riverbeds, glacial tills, and volcanic regions worldwide.

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