What properties do ceramics have?

As we've already seen, the most important general property of ceramics is that they're refractory: they're rough-and-tumble materials that will put up with fair amounts of abuse in the most ordinary and extraordinary situations. Just consider, most of us tile our kitchens and bathrooms because ceramic tiles are hard, waterproof, largely resistant to scratches, and keep on looking good for year upon year; but engineers also put (very different!) ceramic tiles on space rockets to protect them against heat when they whiz back to Earth.

If we're summarizing their properties, we can say that ceramics have:

• High melting points (so they're heat resistant).
• Great hardness and strength.
• Considerable durability (they're long-lasting and hard-wearing).
• Low electrical and thermal conductivity (they're good insulators).