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).
2.35 Carat Princess Shape Diamond Actual Size
This page has a handy photo that gives you the apparent size of a 2.35 carat weight princess shape stone, when viewed in place on the hand of a woman. Some advice for how to use the information on this page is to initially narrow down your size range; then you can go into stores and actually try a few different sized princess shape diamond rings on, armed with this prior knowledge.