Banded Agate (specifically Mexican Lace Agate variety appearance)

Physical Properties

Hardness: 6.5-7 on Mohs scale. Color: Brown, tan, cream, and grey. Luster: Waxy to vitreous. Crystal structure: Cryptocrystalline (Trigonal). Cleavage: None (Conchoidal fracture). Specific Gravity: 2.58-2.64.

Formation & Geological History

Formed through the deposition of silica from groundwater into cavities (vesicles) in igneous volcanic rocks like rhyolite. The banding results from periodic changes in the chemical composition or temperature of the silica-rich fluids over thousands of years.

Uses & Applications

Primarily used for lapidary work including jewelry (cabochons), interior decoration (slabs/bookends), and as metaphysical healing stones. Smaller pieces are often tumbled.

Geological Facts

Agates are unique because no two patterns are exactly alike. The term 'agate' is named after the Achates River in Sicily where they were first discovered. Agates have been used by humans for ornaments and tools since Neolithic times.

Field Identification & Locations

Identify in the field by looking for concentric or wavy banding within a nodule or blocky mass, and its characteristic waxy luster on a fresh break. Common in volcanic regions of Mexico, Brazil, and the Southwestern US. For collectors, look for the 'lace-like' complexity of the bands.

Identified on: 4/17/2026

Mode: Standard