One size does not fit all. However, for the people reading these pages as part of your research before buying a diamond from someone other than myself, I recommend for the masses:
Clarity: VS1 – VS2
Anything clearer than VS1 cannot be seen with the naked eye, so higher clarity is more for knowledge sake than beauty. On the other end of the spectrum, some SI diamonds look great but others don’t. That’s why they’re priced lower. Very poor clarity diamonds look like crap, even from far away. I do not recommend I clarity diamonds or below, ever.
Every site has different words for their cut ratings, which is usually the most important “C” when it comes to sparkle. When naive consumers think they are getting a “deal” on a diamond, this “C” is often one of the things at play. I generally recommend the higher end of the scale. As with all grading, the incremental difference between “highest” and “second highest” will be small.
Color: F – H
Like the clarity, there comes a point where you’re paying for the letter rather than something you can see. An expensive D diamond in no longer D once she applies moisturizer to her hands. I begin to see yellow on I and lower diamonds and while they still look great, if you buy an I or J diamond expect it to be a little dark. That said, an L diamond with good cut and clarity, in the right setting, on the right woman, will look spectacular and cost much less.
The size of your diamond is solely a matter of your and her taste. A high quality diamond looks fantastic no matter what the size. In general, a small, high quality diamond looks better than a large crapola diamond.
If you are buying a loose diamond, keep it simple. A girdle that is thin to very thick will be more difficult to set straight. A very thin girdle will be easier to chip. A thick girdle will add unwanted carat weight to your diamond, making it both expensive and difficult to set.
Fluorescence: Not Strong
Symmetry: stay in the top half of the spectrum.
Polish: stay in the top half of the spectrum.
Certificate: Novice buyers should never buy large stones without a certificate. GIA is the largest grader, is consistent and is the most expensive. GIA does not grade lab-created diamonds. EGL is usually a little less stringent and has several major labs which grade diamonds differently. IGI and AGS both seem to be pretty good, based only on very few certs I’ve seen from those labs.
-Buying a diamond whose price is too good to be true. Most people looking for a “deal” on a diamond get the opposite.
-Don’t buy a loose diamond without first finding a goldsmith who will put it into jewelry for you. Many jewelers won’t work on diamonds purchased elsewhere, because the profit on diamond sales is an essential part of their income.
Fantastic! Now, you can buy a diamond online in as little as 10 minutes. Pay yourself back for all the time you saved with a tall glass of scotch.
While I do not require that customers purchase stones through me, I do not offer free advice (other than what is on this site) about purchasing through other retailers. If you want to discuss a diamond purchase from an outside retailer, I am happy to charge my hourly rate to answer questions, after a deposit has been paid.