Not all ice is mineral ice. Only naturally forming, crystalline ice can be considered a mineral, such as snow, permafrost, and glaciers.
Mineral ice is classified as colorless, according to the Mineralogy Database. Yet, multiple reflections, air bubbles, and soil particles can make ice appear white, blue, or even green.
The GeoSciences Department at Purdue University notes that specific gravity is one of the most important mineral characteristics. Mineral ice floats and has a low specific gravity, approximately 0.917.
Crystals in mineral ice have a distinctly hexagonal shape. These flat crystals combine by the thousands to form large blocks of glacial ice.
Mohs scale of hardness assesses the resistance of a particular mineral against scratching. Ice registers 1.5 on the hardness scale, meaning it can be scratched by a fingernail. By comparison, the absolute hardness of a diamond is 1,600.
Mineral ice is commonly found near the North Pole and Antarctica. Yet, the Mineralogy Database notes that mineral ice can also be associated with glaciers, icebergs, and frozen bodies of water in other regions of the world.