also known as carborundum, is a synthetic compound produced by fusing quartz sand (SiO₂) and petroleum coke in an electric resistance furnace at ＞2,200°C. Its dark color results from impurities like free carbon and iron.  

Key Properties:  

1. Extreme Hardnes， Mohs hardness **9.2** (3rd hardest known material).  

2. Thermal Stability: Refractoriness ＞1,800°C with high thermal conductivity.  

3. Chemical Inertness: Resistant to acids, alkalis, and oxidation.  

4. Electrical Conductivity: Used in semiconductor applications.  

5. High Brittleness: Unsuitable for high-impact conditions.  

Primary Applications:  

Abrasive Tools: Grinding wheels, cutting discs, sandblasting media (for metals, stone, etc.)  

Refractories: Kiln linings, high-temperature ceramics  

Advanced Ceramics: Ballistic armor, mechanical seals  

Electronics: Heating elements, semiconductor substrates (high-purity grades)