Oco Feather Agate with Amethyst Druzy Pair #1

Mineral: Feather Agate (Chalcedony) with Amethyst Druzy Quartz
Origin: Oco Geodes, Rio Grande do Sul, Brazil

This miniature Oco agate pair features intricate feather-like fortification banding surrounding sparkling amethyst druzy-lined cavities.

Oco geodes are formed within volcanic rock and are highly prized for their compact size, detailed agate formations, and crystal-rich interiors. Layers of microcrystalline quartz gradually formed along the cavity walls over millions of years, creating the flowing lace and plume-like structures visible throughout the agate.

The internal cavities later filled with silica-rich fluids, allowing fine quartz crystals to crystallise along the exposed surfaces. Trace mineral inclusions within the quartz produced the soft lavender to smoky amethyst tones visible throughout the druzy interiors.

These specimens display delicate cream, taupe, caramel, and smoky grey banding with dramatic feather formations framing the crystal-lined centres.

Each pair is unique in plume structure, cavity formation, crystal growth, and colour variation.