Corundum

Definition

Corundum is a crystalline form of aluminum oxide, recognized for its exceptional hardness and durability, making it a valuable material in various industrial applications. Often found in its natural form as sapphire and ruby, corundum plays a crucial role in grinding and polishing processes due to its abrasive properties. Its hardness allows it to effectively cut and shape other materials, which is essential for achieving smooth finishes on various surfaces.

5 Must Know Facts For Your Next Test

1. Corundum ranks 9 on the Mohs scale of mineral hardness, making it one of the hardest natural minerals known.
2. In industrial applications, corundum is often synthesized as an abrasive for use in grinding wheels and sandpaper.
3. Natural corundum can come in various colors depending on impurities, leading to the formation of gemstones like rubies (red) and sapphires (blue).
4. Corundum's ability to withstand high temperatures makes it useful in refractory materials and ceramic production.
5. Due to its hardness and chemical stability, corundum is widely used in optics and electronic components.

Review Questions

• How does the hardness of corundum compare to other materials used in grinding and polishing?
  • Corundum is ranked 9 on the Mohs scale of mineral hardness, which places it just below diamond. This level of hardness makes corundum significantly harder than many other commonly used materials in grinding and polishing, such as quartz or silica. As a result, corundum is highly effective at cutting and shaping various surfaces, allowing it to outperform softer abrasives.
• Discuss the role of corundum in industrial applications and its advantages over other abrasives.
  • Corundum plays a vital role in industrial applications primarily due to its hardness, thermal stability, and resistance to wear. Unlike softer abrasives that wear down quickly, corundum retains its shape and effectiveness for extended periods, making it cost-effective over time. Its versatility allows it to be used in various forms such as grinding wheels, sandpaper, and even as a blasting media for surface preparation.
• Evaluate the significance of synthetic corundum production in modern manufacturing and how it has impacted traditional sources of abrasives.
  • The production of synthetic corundum has transformed modern manufacturing by providing a consistent and reliable source of high-quality abrasives. This advancement has reduced dependence on natural corundum sources, which can be limited and costly. Synthetic corundum can be engineered to specific sizes and properties, enhancing its effectiveness for various applications. This shift not only improves efficiency but also helps maintain cost control in industries reliant on abrasive materials.

Related terms

Abrasive:

A material used for grinding, polishing, or cutting other surfaces, typically characterized by its hardness.

Sapphire: A precious gemstone that is a variety of corundum, typically blue but can be found in a range of colors.

Aluminum Oxide: A chemical compound with the formula Al₂O₃, commonly found in corundum and used as an abrasive and in ceramics.