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).
1.30 Carat Actual Size
An average round diamond with a 1.30 carat size has a diameter of 7.1 mm, although this can vary slightly if the cut is shallow or deep. The ring shown in the picture is a US size six; this is equivalent to an L 1/2 size in countries like Australia and Britain, and is an average ring size. Be aware that image like this one are limited in what they can show - women's hand sizes can vary hugely. The "first impressions" size of a diamond is influenced by what it is shown against - the hand - a petite hand will make the diamond appear proportionately larger, with the reverse applying as well.