Ingenous rocks and metamorphic rocks
The answer is : Diamonds are a nonrenewable resource, making them scarce.
Diamonds are very valuable gemstones. They form in the ground and they take from one to five million years to form properly.They appear in different color variations but they can also be colorless.
Nonrenewable resources are those that <em>can not be easily replaced or replenished.</em> As diamonds take so long to form, their amount in the world is limited and they are not always available.
There is no such things as artificial diamonds, they are therefore irreplaceable which makes them<em> a nonrenewable resource.</em>
