One carat is equal to 200 milligrams or one-fifth of a gram. Therefore, a diamond that is three-quarters of a carat is also referred to as weighing 75 points. Clarity clock Clarity refers to the presence or absence of inclusions in the stone. An inclusion is a natural imperfection created when the stone formed in the earth. It can be created by a substance that is foreign to the chemical composition of the stone, by an internal crystal that was not fully formed, or by a small fracture within the stone.
Many gemstones have inclusions that are characteristic to that stone and help in identifying it.
For diamonds, their clarity is graded on a scale from Flawless to Included. All grading is carried out under 10X magnification. No internal or external inclusions can be seen. Inclusions are difficult to see by untrained individuals. Inclusions are clearly visible with magnification.