What kind of diamonds are there?

Answer 1

There are four types of gem-quality diamonds: Type Ia, Type Ib, Type IIa, and Type IIb. These descriptions describe raw diamonds, not finished gemstones. Only about 20% of all diamonds mined are of gem-quality.

• Type Ia is the most common type of diamond, and contains pairs of nitrogen atoms at a concentration of less than 1%.
• Type Iab diamonds contain large aggregates of nitrogen atoms, up to about 5%.

Most gem-quality diamonds are made up of Type Ia and Iab materials.

• Type Ib diamonds make up less than 1% of all gem-quality diamonds, and contain less than .05% of nitrogen atoms randomly scattered in the stone. (This is the type of diamond common produced synthetically by the HPHT -- high pressure/ high temperature -- method.)

Type II diamonds lack nitrogen. These stones were formed under higher pressure for longer periods than Type I diamonds, and are more irregular in their native shape.

• Type IIa diamonds lack impurities and have the highest thermal conductivity of all diamonds. Because of their creation processes, several colours of diamonds occur in this type, including pink, red, or purple. (This type of diamond can be produced by the CVD -- chemical vapor deposition -- method.)
• Type IIb diamonds -- the rarest of all diamond types making up only about .1% of all raw diamonds found, contain significant boron impurities. These diamonds contain uncompensated electron holes, making them p-type semiconductors. These diamonds can be colourless, but are also blue and blue-gray.

There are vagaries among these types and ultraviolet and infrared absorption tests are required to precisely identify a diamond type.

Answer 2

There are natural diamonds, which are formed over millions of years deep within the Earth's mantle, and lab-grown diamonds, which are produced in a controlled environment to mimic the natural process. Additionally, there are different types of diamonds based on their color, clarity, cut, and carat weight, all of which contribute to their overall quality and value.

Answer 3

There are four different types of diamonds. Natural, synthetic, irradiated, and non-irradiated. These diamonds can come in several sizes, shapes, and colors.