Your answer depends on the cut you are measuring. If the gem is a round cut, the carat weight will be about .10 carats.
If the diamond is a round brilliant cut, the 3mm measurement at the girdle indicates that the diamond weighs about 1/10th of a carat, or .10 carats.
Two grams is 10 carats.
10 carats
The wic means "Weight In Carats". So a 10k wic inside a ring means that the ring is 10 carats
One carat equals .02 grammes, so two grammes equals 10 carats. Five times that much means that you'd have about 50 carats of diamonds. Since every diamond is valued according to its cut, clarity, carat weight and colour, all these variables would affect the value of the diamonds in the cache.
21.6 carats
Since you only give one measurement, one must assume that it is a girdle diameter measurement. If the stone in question is a round diamond, at this measurement it can be estimated that the diamond weighs between 4 and 5 carats.
10 dollars
10
A 10 carat diamond weighs 10 carats. Apparently, you want to know how a 10 carat diamond might look on the 'big-ness' scale. If the stone is a brilliant cut, it will be around 10MM at the girdle. Explore the link below to see the visual sizes of other cuts and carat weights.
would mean 9-10 carats