Greenstone

Hardness: 6-7 (Mohs scale), Color: dull green to grey-green, Luster: earthy to waxy, Crystal Structure: fine-grained (aphanitic), Cleavage: poor or none, Specific Gravity: 2.8-3.0

Formed through low-grade metamorphism of basaltic or similar mafic rocks under low temperature and pressure conditions, typically in subduction zones or orogenic belts. Many date back to the Archean or Proterozoic eons.

Used historically for stone tools and weapons (ax heads), current use in crushed stone for road construction, and occasionally for decorative landscaping or lapidary work.

The green color is primarily due to the presence of chlorite, epidote, or actinolite minerals. Greenstones are often found in 'Greenstone Belts', which are significant hosts for gold and silver deposits around the world.

Identify by its distinctive greenish hue and high density. It lacks the slaty cleavage of slate and the crystalline visible grains of diorite. Common in riverbeds (as a rounded cobble) or rocky outcrops in mountainous regions.