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).
What Does a 1.69 Carat Diamond Look Like on a Hand?
If you are hesitant to put too much stock in a simple picture, what you can do is measure the width of your finger and compare it to the 7.8 mm average diameter of a 1.69 carat diamond. This image is scaled to show a size L 1/2 ring (British and Australia), which is equivalent to a US size 6 ring. Your fingers could be quite a bit thicker or thinner than the ones of the woman in the picture, which are quite thin - be sure to keep this in mind when you're looking at the picture. The "first impressions" size of the diamond depends heavily on what it is shown against - her hand - a small hand will cause the diamond to appear significantly larger, with the reverse applying as well.