Eclogite

Physical Properties

Hardness (7-7.5), distinct red-orange color from garnet and green from omphacite pyroxene. It has a high density and granular texture, typically showing a massive or slightly foliated structure.

Formation & Geological History

Formed under conditions of high pressure (>1.2 GPa) and moderate to high temperatures at depths of more than 45-60 km in the subduction zones of the Earth's mantle.

Uses & Applications

Primarily of interest to geologists and collectors; can be used as a heavy-duty construction aggregate or very rarely as a source of industrial garnet and low-grade jade substitute.

Geological Facts

Known as the 'Christmas Rock' because of its distinctive red-green color pattern. It represents a fragment of the Earth's deep crust or mantle brought to the surface through tectonic processes.

Field Identification & Locations

Identify in the field by its high specific gravity (it feels heavy for its size) and the presence of red pyrope garnets set in a grass-green omphacite matrix. Commonly found in mountain belts where subducted plates have been exhumed.

Identified on: 4/29/2026

Mode: Standard