
This post could very well have been called “Why should I buy a hearts and arrows CZ” because that is precisely the question that I am going to answer. But I am also going to tell you why an aspiring gemologist should buy one of our premium-quality CZ’s. Or, even if you have no aspirations to be a gemologist but you want to learn more about stones this applies to you as well. If you want to be a better consumer of stones this is every bit as important.
First, to get this out of the way, we only sell one grade of CZ. This grade has different designations depending upon the manufacturer, but the tolerance is unmistakable. It is held to within 1/100th of a millimeter for most sizes. Some manufacturers call it AAAAAAA or 7A grade, while others call it hearts and arrows 5A. The bottom line is that it is the most precisely cut cubic zirconia that you can buy anywhere at any price.

But let’s get to the meat of this argument that you should buy one. Quick- is a stone dense or not? Huh? Uhhhhhh. Yeah, that’s what I thought. You don’t have a reference and that is why you don’t use this test. You need to heft a stone by bouncing it on your palm a few times- toss it and catch it. Get some air between your palm and your stone- at least 12 inches. Feel it hit your palm- always the same palm. Now look at your stone. Is it opal? Is it diamond? Is it CZ? Well, if you practice this test with a CZ that you buy from Tip Top Gem you will have a very good reference for what “dense” is. A CZ will feel heavy compared to a diamond of the same size and especially compared to an opal. Do you think you don’t need this test, or this reference? You’re wrong. It is fast, easy, and free. It is also very accurate if you practice it, and it can help you separate CZ from some other colorless stones. It can also help you separate yellow CZ from sphene, or yellow CZ from yellow sapphire. Get to know the density of CZ and you are well on your way to getting a feel for many other stones.
Answer quickly now- no peeking. What is the luster of stone “A”? Uhhhhhh. Yeah, again. Well, CZ is an excellent example of subadamantine luster. If you know that a model stone like CZ is subadamantine you will surely be able to separate vitreous luster from adamantine. I know that by now all of the CZ you have seen in my listings seems like a bargain, and you are kicking yourself for not buying any in the past. I forgive you. Go bid. Remember, diamond has adamantine luster- in fact, adamantine means “like a diamond”. That makes sense. But also remember this. Vitreous luster is the most common luster for gemstones to have, so if you can spot subadamantine luster with one hand tied behind your back you are well on your way in the Gem ID game. Remember very few stones have adamantine luster- diamond and zircon are perhaps the most common of these. Demantoid garnet can also display adamantine luster.

If you don’t have a lot of experience judging luster, or it is not clear in your mind, remember these basics. You have to look at the reflection of the light from a stone’s surface. There are varying degrees of “crispness” or “whiteness” of that reflection. Vitreous means “like glass” so you can expect the reflection to be a bit grayish and not perfectly bright and crisp when it is reflected from the surface of a gemstone that has vitreous luster. Adamantine luster is like a diamond, and it is the ultimate brightness or crispness and it has the least amount of grey. It is a clean, very white reflection. Subadamantine is less than this, but it is not as far down the scale as vitreous. It will be between vitreous and adamantine on the scale. It will not be as white and crisp and bright as the reflection of light from the surface of a demantoid garnet or a diamond or a zircon. But it will not fall down the scale to the point where it has a grey tinge like a vitreous stone shows. Remember that polish marks, burned facets, or any number of surface defects will affect luster. When we say a demantoid garnet has adamantine luster, that means that it is the highest luster that it can expect to achieve with good polish.

Please allow me another word on luster. Now that every idiot and his even less intelligent brother can sell online we are inundated with people talking about the luster of gemstones. Stop, people. Luster is NOT brilliance. Luster is a property that can be observed when viewing the reflection of light from a gemstone’s SURFACE. It is also constant- diamond is virtually always adamantine, CZ is virtually always subadamantine, and quartz is virtually always vitreous. There is some wiggle-room, of course, as luster can vary from specimen to specimen of the same variety. But let me be clear on this point: you can not recut a stone to give it better luster! A well-cut stone does not have better luster than one that is poorly cut- they are the same. You can re-polish a stone to give it a better luster. But you will not be able to change the pavilion angle to improve its luster because luster only deals with the reflection of light from a stone’s surface.
If you are interested in learning to judge brilliance, and anyone who wants to be a better gemologist or a better gemstone consumer should be, the hearts-and-arrows CZ is an excellent control stone. This can show you what is possible. If you expect a stone to be better than this, your expectations are too high. If you have never seen a stone with nearly 100% brilliance, you are in for a treat as well as a learning experience. Just like your CZ can serve as a barometer for density, it can also serve as a model for perfect brilliance.

In the colored stone world we know that we have to live with imperfection. Beauty and perfection are entirely different, and few would argue that how beautiful something is depends upon how close it comes to perfection. But the hearts-and-arrows CZ that we offer is a superb model for perfect polish. You are not likely to find any polish lines, those little parallel lines on facets that tell you that the cutter was not so diligent when he was creating a gleaming luster on the stone’s surface. Each facet of 7A grade CZ is polished to perfection. There are no scratches, polish marks or lines, in fact- there is nothing to interfere with the stone’s subadamantine luster. It is universally shiny from one edge of a facet to the other. If you need a model for polish or if you want to learn to judge polish accurately then buy one of these stones.
Another aspect of a stone’s character that you will be asked to assess when doing a basic ID is the stone’s dispersion. Here we get into another tussle with the online salesfolk. Fire has a very specific meaning in the world of gemology, and if you sell colored stones online you should know what that meaning is. The ability of a stone to break up white light into its component rainbow colors is called “fire” or “dispersion”. They mean the same things to gemologists and to qualified, knowledgeable salespeople. Fire is not brilliance. A stone cut from quartz may have a huge amount of brilliance, but it will not have any fire. When you look at it you can not see rainbow colors like you can with diamond or (to a greater degree) CZ. Remember that CZ has more dispersion, or rainbow-colored fire, than diamond. It has- some would say- too much. If you bounce a stone on your hand and it is too heavy for the size, and then you notice that it has a lot of dispersion- it might well be a CZ.

Are you still unconvinced? Well, for fun you could tell your friend (spouse?) that your 10mm hearts-and-arrows CZ is a world-class 3.66 carat diamond. Yes, unlike lesser CZ ours really does appear very transparent and is an equivalent to a “D” color diamond- which is totally colorless. There is not the slightest shade of yellow, nor are the stones “milky” as some CZ tends to be. And just to make my point about density- note that this 10mm stone looks like a 3.66 carat diamond. You could take a 3.66 carat round diamond out of its mount and put this stone in, no problem. But how much does this 10mm stone weigh? Well, hold on to your teeth Ethel- about 6 3/4 carats!!! Yes, CZ is heavy.
If you have any questions about Gem ID, or about our CZ, or about anything at all gem-related please feel free to send me a note. There is a contact form link in the margin over on the right side and your message will go straight to my inbox. I would be happy to help in any way that I can!
