WHAT IS CARAT WEIGHT?
This is a term we are all familiar with. Just like diamonds, tanzanites are weighed in carats. The higher the carats, the heavier the stone.
MEASURING SIZE FROM CARAT WEIGHT
If you place a one-carat diamond next to a one-carat tanzanite, their sizes will not look the same. This is because diamonds are heavier than tanzanites.
In addition, very different cutting styles are used for diamonds as opposed to colored stones, and the proportions between the two are usually also different as a result.
You should evaluate a tanzanite’s size by viewing it from the top, because that is how it will be seen when set into a ring or jewelry item. To assess the stone’s size, check it face-up measurements (length x width).