mineral

Grape Agate (Amethystine Chalcedony)

Silicon Dioxide (SiO2) with impurities

Hardness: 6.5-7 (Mohs); Color: Pale lavender, white, or light gray; Luster: Waxy to vitreous; Crystal Structure: Trigonal/Microcrystalline; Cleavage: None (Conchoidal fracture); Habit: Botryoidal (grape-like) aggregates.

Hardness: 6
Color: Pale lavender, white, or light gray
Luster: Waxy to vitreous

Identified June 2, 2026More mineral →

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Physical properties

Formation & geological history

Formed through volcanic processes in the cavities of andesite or basalt. Silica-rich hydrothermal fluids precipitate in voids, creating spherical aggregates. Most specimens date from the Miocene epoch.

Uses & applications

Primarily used as decorative specimens for collectors, metaphysical use, and high-end artisanal lapidary work.

Geological facts

Despite the name 'Grape Agate,' it is technically a botryoidal chalcedony rather than a true banded agate. It was only discovered/marketed widely from Indonesia (the Manakarra region) around 2016.

Field identification & locations

Identified by its unique 'bubbly' or tiny ball-like surface texture. Look for the distinctive botryoidal habit and the characteristic violet or pale waxy white color. Mostly found in Indonesia.

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