0.51 Carat Diamond
A diamond of size 0.51 carats measures about 5.2 mm in diameter.
The diamond is identical in size to a a diamond of size 51 points. It weighs exactly 102 milligrams.
For comparison, a diamond with half its carat weight has a diameter of approximately 4.1 mm. A diamond with double its carat weight has a diameter of approximately 6.5 mm.
As you can see there is no doubling in the diameter of a diamond even though the diamond's weight is twice as much, so in a way you get diminishing "bang for your buck" when you go up in carat weight from 0.51 carats.
An explanation for why a 2 carat diamond does not look to have twice as large a diameter as a 1 carat sized diamond is to do with a relationship between volume and area. You can reason about it by taking the example of people - compare the heights of a 200 pound person with a 100 pound person and there's rarely a factor of two in their height difference (i.e. if one's 6 feet tall the other is rarely as short as 3 feet).
One of the best ways to get a feel for diamond size is to look at a few! James Allen has an online tool for finding diamonds where you can select the range of diamond sizes you're interested in and see ACTUAL PHOTOS OF THE DIAMONDS.
For example, in the screenshot below, I'm looking for diamonds between 0.93 and 1.02 carats in size. You can click on the image to go try some searches yourself. I've circled in red where you change the size range you want to search for.
Screenshot of the diamond search tool provided by James Allen.
You can also save 10% on your engagement ring setting once you've picked a diamond. Engagement Ring Guru has partnered with James Allen to provide you with a unique 10% off any engagement ring setting coupon code. Just type in "ringgu10" during the purchase process and you'll get 10% off the ring setting price (doesn't include the diamond).
