Grape Agate

Description

Grape Agate — botanically named for its resemblance to clusters of tiny grapes — is a botryoidal chalcedony found almost exclusively in the Mamuju region of West Sulawesi, Indonesia. The mineral forms dense, spherical aggregates of microcrystalline quartz in shades ranging from pale lavender through violet to deep purple, with individual spheres typically 2–10 mm in diameter. The colour is attributed to trace amounts of iron or manganese within the chalcedony structure.

Grape Agate entered the collector market seriously around 2016, when Mamuju specimens first appeared at international shows, and quickly became one of the most sought-after collector minerals of the decade. High-quality pieces with uniform deep purple colour, tightly packed unbroken spheres and good lustre are the most desirable. Indonesia remains the only significant source of this distinctive botryoidal form.