Diamond Ring Buying Guide and Advice: What to look for in a diamond (Page 2)
Clarity is another important part of a diamond. Almost all diamonds have inclusions (little things inside of a diamond that happen when diamonds are formed). Most people don't know this, but probably everyone you know of has inclusions in their diamonds, but the extent of these vary greatly. They go from invisible to the naked eye to visible to the naked eye. The scale for this is FL (flawless), IF (internally flawless), VVS1 and VVS2 (very very small inclusions), VS1 and VS2 (very small inclusions), SI1 and SI2 (small inclusions), and I (inclusions). FL and IF diamonds (flawless) are VERY rare and VERY expensive. Unless you want to spend several thousand more than normal on a small diamond, you probably shouldn't look at these. Besides, no one can tell the difference between flawless diamonds and VS and SI diamonds usually. For your sake, you should look more at VS and SI's. A VVS doesn't have much of a difference compared to a VS, and some SI's you can get that look like VS's. So let's focus on VS, SI, and I. Almost all VS diamonds have inclusions that you can't see to the naked eye. Under a 10x microscope, a trained gemologist might be able to see something VERY tiny. As for SI diamonds, some of them are invisible to the naked eye (almost all). Under a 10x scope, a trained gemologist would be able to see something small a little easier than he/she would with a VS. Stay away from I's, as those you can see with the naked eye (from the top of the diamond). Sometimes they'll be black lines or dots, while other times they'll be cloudy parts on the top of a diamond. Sometimes you might be able to find an alright I diamond and save a lot, but it's all up to you (if there's a noticeable mark on an I diamond only on a side, some people can try to block it out by covering it up with the setting of the ring).
Most important in all of this is to ask for an eye clean diamond. Eye clean means that you can't see any inclusions with the naked eye. Almost all VS diamonds are like this, and some SI diamonds are like this. If you find an SI diamond that is eye clean, you should go with that, because you'll save a couple hundred dollars for something that you won't be able to tell the difference with between a VS and SI. Other times with an SI diamond, you'll see nothing from the top of the diamond (the most important part), but you might see something REALLY faint on the side depending on the light you're in. A small secret is that most diamonds that people have usually have this, but not many people notice it. In my opinion, first-time buyers are too obsessed about this and tend to buy a much higher quality diamond than they really need to, as they won't be able to notice the difference anyway. Don't get me wrong, IF, FL, and VVS diamonds are great picks if you have the extra money and several hundred to potentially one or two thousand dollars more don't mean a difference, but for those looking for a great diamond at a great price, you shouldn't worry about it this much. Below is a chart showing different clarities. I should warn you that this chart looks worse than it really is in real life (and keep in mind, they grade this based on looking at it under a 10x microscope). Again, SI diamonds can often be eye clean (can't see anything with the naked eye, especially from the top).
Remember to stay away from most I diamonds and stick mainly to VS 1-2 to SI 1-2 (SI's are usually the better deal if they're eye clean, as you probably won't be able to tell the difference). If you have the extra money, you can get a VVS, but most people won't be able to tell the difference from a VS or SI (FL and IF are only if you're REALLY obsessed or if you plan on buying diamonds as investments and not for jewelry).