The info you posted is very interesting. The quality of gemstones like diamonds is often characterized by the grading scale used by the GIA, color, claity, cut (not shape, but optimization compared to ideal standards) and carat weight. The better the grade, the more expensive the diamond. And when you combine the different characteristics, the prices of better diamonds can be many times more expensive than lower quality diamonds.
Moissanite can vary from stone to stone among these same characteristics. Color is generally the most obvious characteristic that people focus on because it's the easist to see. Earlier mossanite often had distinctly less appealing color (more yellow or green caste). More recent manufacturing techniques have produced better color stones (better meaning less color) which look like better quality diamonds.
In the diamond world D-E-F are the best diamonds in terms of color grading (truly colorless) and the most desireable diamonds. G-H-I color graded diamonds show a little more body color, but are still lovely and in todays world G-H color diamonds are very sought after.
J-K-L color diamonds can still be very pretty, especially if the stones are good quality and well cut. But if you look at the J-K-L color diamonds against a white piece of paper, the stones will be more yellow. In a piece of jewelry, however, depending upon all the other factors, and the size of the stone, and how it's set, it can still be
lovely.
As we are taling about diamond quality, I must say that many (most) of the diamonds that are sold today are so far from the top or middle end of the color and claity scale. The smaller stones used in multi stone designs today are often hightly included and well down the color scale.
Back to moissanite, different manufacturers use different names to distinguish the overall quality of their stones. The collection name often encompasses both the color and clarity assessmet of the stones, and possibly also the quality(precision) of the cutting.
Charles and Covard held the original pattent on moissanite namufacturing. In the last few years, other companies have produced moissanite stones. As consumers, the more we can learn about the relative quality grading of the stones, the better decision we can make. Since most of jewelry buyers aren't trained or interested in understanding all the technical quality measures, it's helpful when a company groups their stones into collections and gives each one a name. As long as we have a sense of the differences between the collections characteristics, we can make better decisions. Comparing one manufacturer to another is still difficult, but some info is better than no info.
Generally stones set into silver are of lower quality than the stones a manufacturer will use for gold or platinum setting. Of course if you are buying loose stones, you need to understand something about the stones to do a compare.
To add to the confusion, different people have different preferences.... based on what appeals to them and also what they are used to seeing. If every diamond you have seen is a mid level quality and someone has a top quality diamond.... that top quality diamond will look fake to you. To your eye, in your mind, the brightness, sparkle, and clairty of that top quality diamond doesn't fit with what a diamond looks like in your experience. The same is true with man-made stones like moissanite. If you are used to seeing mid range diamonds then a top quality mossanite will look fake. And moissanite does look different than a diamond, even when comparing top quality of a diamond to top quality of moissantie. Moissanite will display more fire and brilliance.
So where does this leave us....I'd say, pick the best quality (best color...as close to colorless, and best clarity) that you can afford. Compare the cost and the look of the same size pair of studs in the 2 top Charles and Covard grades.
Generally, G-H-I color stones are considered very good, especially for earrings, so don't feel you are making a bad choice if that is what you opt for. Just be sure to understand return policies in case what you pick doesn't delight you.
If you go with another brand, do your research to understand as much as you can about their stones. The top grade from another company might be the middle grade or even the lowest grade from Charles and Covard.
Good luck. Hope this helps. There are some posters who have purchased moissanite and maybe they can provide info on where they have gotten stones that they think are beautiful and worth the money.
I own diamonds and CZ, but no moissanite. I think that the better quality moissantie is beautiful, but given what I already own, I haven't seen the need to invest in moissanite. If I was starting from the beginning, I might make different choices, I don't know.
The one thing I do know is that you need to love what you buy and not feel you compromized. If you are going to spend a lot of money on a moissanite or a diamond, you should be delighted with what you get and not feel you wish you could have gotten better or bigger. Once the studs are on your ears most people won't have a clue if they are diamond, moissanite, or CZ.... regardless of how 'expert' they think they are. Because my friends know that I have diamonds, they assume every time I wear studs, they are the diamonds. And many of my friends are relatively knowledgeable about jewelry. Most of the time, the studs are the CZ, with the diamond ones tucked safely info the safety deposit box in the bank. The only time they question if the studs are real is when they are very large stones, over 2 carat each ear. Smaller stones, even my 20 year old diamonique studs set in 14K still look wonderful and sparkle beautifully if I keep them reasonably clean.