Your diamond may be a black diamond, if it's a diamond. There is a black diamond scale which ranks stones with AAA grades.
Diamonds that are flawless are labeled IF for internally flawless, or FL for flawless.
This stone could also be something other than a diamond.
Only a gemologist can give you the value, based on its cut and determination of how the stone achieved its colour.
A 1.00 point diamond is one carat, so a .12 point diamond is a little over 1/10th of a carat.
it depends what style diamond it is.
If the diamond is cut, 4-point may refer to its weight, would would otherwise be expressed as .04 carat, or 4/100ths of a carat.
A forty-point diamond is nearly half a carat, which would be fifty points.
The depth measurement depends on the cut of the diamond, not the carat weight.
Total carat weight which the sum of the individual carat weights of all the diamonds in a piece of jewelry. One carat is divided into 100 parts, called points, so, a 25-point diamond weighs a quarter carat and a 50-point diamond weighs a half carat
Carats in diamond weight can be divided into 100ths, meaning that a quarter carat stone could be described as a .25 carat diamond. In your case, you could describe this stone, as just over half a carat or .58 carat diamond. Less than full carat stones are also called points: a 58 point stone in your case.
A 14-point stone is 14/100 of a full carat.
Both versions of the description you give, 20 point and 0.2 carat mean that the stone is roughly one-fifth of a carat in weight.
One point eight carats.
A 60-point diamond weighs just over half a carat (.50 carats). The size of the ring is not related to the weight of the diamond.
Every diamond is worth what someone will pay you for it. You can buy a 25 point diamond -- 25/100ths of a carat -- today at Blue Nile and spend about US$215. A four-point diamond is 4/100ths of a carat, meaning that it is very small for a diamond -- between 2 and 2.5MM at the girdle if the diamond is a round brilliant cut.