Toughness is the ability of a material to resist breaking. Spinel is very tough. It does not exhibit cleavage (planes in its crystal structure that are prone to separation) like diamond and topaz. It is not as brittle or prone to fractures as emerald, topaz, and many other hard gems. Spinel is one of the tougher gem minerals.

Spinel is also very hard – only a few materials can scratch it. Spinel is tough – it does not break easily. Those two qualities make spinel one of the most durable gems. The most durable gems are both hard and tough. Spinel is durable enough for any jewelry use.