Blue Quartzite

Hardness: 7 (Mohs scale), Color: Pale blue to sky blue, Luster: Vitreous to dull (grainy), Crystal Structure: Trigonal (granular texture), Specific Gravity: 2.6 - 2.7

Formed through the metamorphism of quartz-rich sandstone under intense heat and pressure. The blue color often results from the presence of microscopic inclusions of minerals like dumortierite, blue tourmaline, or crocidolite.

Used primarily for decorative purposes, landscaping, aquarium stone, and occasionally carved into cabochons for jewelry or tumbled stones.

Quartzite is so hard that it will scratch glass. While pure quartzite is white or gray, it can become beautifully colored based on mineral impurities that get trapped during the metamorphic process.

Identify it by its extreme hardness (cannot be scratched by a steel blade) and its granular, sugary texture on broken surfaces. It is commonly found in ancient mountain belts and shields.