Quick and Easy Buying Guide
Carat weight: 1 carat = 200 milligrams = 6.5 mm diameter. Doubling weight doesn't double diameter.
Diamond clarity: FL/IF/VVS/VS = super expensive, near perfect. SI = best value if you can check a photo for obvious inclusions (defects).
Color: D-G = colorless, expensive, only if you have money to burn. H-J = best value. Can go lower in gold metal settings than white metal.
Cut: Better cut ratings let more light into a diamond, making it sparkle more. Very important property, don't skimp here.
Set a budget and minimum cut (Premium). Go J color for gold and I/H for white metals. Go searching for SI1/SI2 clarity diamonds at James Allen. Pick a diamond with small/no inclusions. Choose a ring setting and buy it risk-free (60-day returns).
2.42 Carat Diamonds
The shallowness of a diamond, which depends on how the diamond has been cut, will affect the relationship between carat weight and diameter of the diamond - because of this reason, 2.42 carat diamonds will only average a width of 8.79 mm, but will not always be precisely this width. To help you analyse your various diamond options, one measure you can use is the cost per carat measure.
Sponsored Links
There's a lot of hearsay on the internet about the average size of a diamond used in a typical diamond engagement ring - it's around half carat - but that of course doesn't give you any information about the typical clarity or colour of the diamond, and that in itself should tell you how useless that statistic is in isolation. Carat size is only one that property out of a number that you should be considering. You should also consider a diamond other properties such as cut, because this will have a drastic effect on how well the diamond sparkles.
Manners must adorn knowledge and smooth its way in the world, without them it is like a great rough diamond, very well in a closet by way of curiosity, and also for its intrinsic value; but most prized when polished. Lord Chesterfield .