Massive crystallized shungite. Shungite crystals are approximately 8mm to 15mm in size. Shungite is a relatively new mineral, defined as an amorphous variety of graphite of deep black color, similar in appearance to black coal. Chemical formula: Carbon, Hardness: 3.5 - 4; Density: 1.8 - 2.0; Its main components are: coal: 30%, quartz: 45%, compound silicates (micas, chlorites): 20%, sulphates: 3%, others - 2%. Scientists estimate that shungite is at least 2 million years old.
