Which gemstones can be compared with diamonds? And which of them look most like these sparkling stones? Here we describe the most popular alternatives to mined diamonds from which you can choose what fits you most. Learn how close diamond simulants can be to real diamonds (and for how long they will stay like this) and feel free while choosing a suitable simulated diamond.
What is a simulated diamond?
Simulated diamonds (also diamond simulants or diamond imitations) are called stones or materials that look like diamonds but without the same chemical, physical and optical properties. Different natural or lab-created stones can be used in jewelry as diamond imitations, but during jewelry appraisal, they will never be confused with real (natural or lab-created) diamonds.
However, to the naked eye of an average buyer, some diamond simulants will totally appear like real diamonds and don’t change these external qualities over time.
Further, we will concentrate on the most popular diamond simulants but firstly, let us once more distinguish between lab-created diamonds and diamond simulants.
Lab-created Diamonds vs. Diamond Simulants
Lab-created (also man-made or synthetic) diamonds are diamonds, chemically and physically the same as natural diamonds, but made by man in a laboratory (e.g., HPHT synthetic diamond, CVD synthetic diamond). Lab-created diamonds are structurally the same as mined diamonds, they will also test positive on a diamond tester in a laboratory.
Simulated “diamonds” or diamond simulants are chemically or physically. They are just other stones or materials with different atomic structures. Hence, they will have different chemical and optical qualities which however may be quite close to the qualities of a real diamond. Diamond simulants can be made in the laboratory as well as any lab-created stones. They can also be found in nature as, for example, colorless sapphire. Some diamond simulants may even pass the basic diamond tester (read more and you will know which), but they are still not diamonds.
Lab-created diamonds vs. Diamond Simulants
Now we are coming to the question which stones (or materials) look like diamonds. There are different gems like cubic zirconia (CZ), moissanite, as well as clear gemstones like white zircon, white sapphire, topaz, quartz, and some others. All of them are used in jewelry because of their outer similarity to diamonds. Still, each of them has some qualities different from others.
This mineral was discovered by the French chemist Henri Moissan while examining rock samples from a meteor crater in 1893. At first, he mistakenly identified the crystals as diamonds, but in 1904 he identified the crystals as silicon carbide. The mineral form of silicon carbide was named moissanite in honor of Moissan.
This mineral can be found in nature but in such less quantities that you will not meet natural moissanite in jewelry at all. Natural moissanite is extremely rare, it comes in tiny crystals. So for jewelry, synthetic moissanite was created in a lab.
Lab-created moissanite is probably the best diamond simulant and here is why:
- Synthetic moissanite can easily be colorless to nearly colorless with high clarity. The most important thing is that moissanite doesn’t change its purity over time and it does not become cloudy, dull, or fade. Moissanites are just pure as diamonds and will stay so.
- Round colorless moissanite has the most diamond-like properties. You would be puzzled while trying to tell the difference. So, the ideal cut diamond properties can be easily replicated in moissanite.
- Moissanite’s hardness is 9.5 on the Mohs scale which makes him the hardest of all the diamond simulants. The only stone that’s known to be harder than moissanite is (such a surprise:)… a diamond with its 10 on the scale.
- This hardness brings us to the next point: moissanite as a diamond is very durable. For a buyer of a moissanite ring, it means that his stone will be extremely resistant to scratching and abrasion and perfectly suitable for everyday wear. The only minerals that can scratch a moissanite are diamonds and other moissanites.
- Actually, moissanite’s qualities are so close to diamond that a basic diamond tester typically can’t tell moissanite and diamonds apart. Though any other diamond simulants this tester will distinguish immediately.
Still, there are some differences between moissanite and diamond. But you’ll see that in this case differences hardly mean disadvantages.
- One of the points where Moissanite outperforms diamond is sparkle. It has more fire (colorful sparkles), brilliance (white sparkles), and luster (the general radiance of the stone) than diamond. That’s not an opinion, it’s based on actual measurements: moissanite refractive index — the bending of light as it passes in or out of a gem — is considerably higher than diamond’s.
- On the jewelry market, moissanite costs 90% less expensive than a comparable diamond. The lower price of moissanite makes it possible to get a diamond-like yet larger than a diamond for less money. You may have, for example, the 1.5-carat moissanite that looks almost like a 1.5 very expensive diamond (except maybe a moissanite will sparkle more).
- For the eyes of an average buyer and even a standard diamond tester, moissanite is actually indistinguishable from a diamond, as already mentioned. Still, unlike diamond, moissanite is an electric conductor. The test for electrical conductivity (or in other words a Moissanite tester) is often used to tell these two apart.
Other most common diamond simulants are glass (i.e., rhinestones) and cubic zirconia (CZ), both artificial materials. Some others, such as strontium titanate and synthetic rutile have been created in the lab after 1950, but as Wiki and GIA states these are no longer in common use. Still, you can find some of them on the market and in old jewelry.
The second most popular diamond simulant is cubic zirconia or CZ. It’s a synthetic material grown in the lab specifically as a diamond equivalent, but its atomic structure is completely different from diamond, as well as its chemical and physical qualities.
Most diamonds often contain inclusions, even flawless. In fact, this is one main way that jewelers can tell CZ and diamonds apart – by CZs lack of flaws. However, CZ can become yellowish over time.
The hardness of a CZ is 8.5 on the mohs scale. It means, CZ is also a hard stone but is more easily scratched and damaged than a diamond. One of the best things about CZ is that it is much more affordable than diamonds. The second is that they are lab-created in many colors. Colored diamonds, on the other hand, are extremely expensive so colored CZs can be a nice affordable solution for a colored diamond-like ring.
Cubic Zirconia vs. Natural Zircon
Don’t confuse Cubic Zirconia CZ with zircon. Natural zircon is one of the oldest minerals on earth zirconium silicate, whereas cubic zirconia is made of zirconium oxide. Their names include the word “zirconium” because both these materials contain the basic chemical element zirconium. But the structures of both cubic zirconia and zircon are different as well as their qualities.
Besides, CZ and zircon differ from each other in the following ways:
- A natural zircon was widely used in jewelry in the past. It means you can find this natural gemstone in some old jewelry pieces. Experienced jewelry collectors and informed consumers like this gemstone. The CZ, even though it has been found in nature before, is a lab-created gemstone and is, therefore, not natural and even not considered a mineral. You will find a CZ easily nowadays in contemporary jewelry pieces. It’s especially beloved as an affordable diamond simulant, as mentioned above.
- Zircon has very high luster (refractive indices, RI) giving it lots of brilliance and rainbow flashes of fire. Besides, a natural zircon has double refraction, it displays excellent fire and gives off the illusion of having more facets than it really does. CZ has an RI 2.15 – 2.18, which is higher than zircon. However, although both stones sparkle, a CZ cannot match the higher level of brilliance that a zircon has.
- In terms of hardness, cubic zirconia ranks 8.5, and zircon has something between 6 to 7.5 on the Mohs scale, depending on the quality of a stone. So, a natural zircon is less durable than a CZ.
- The natural zircon varies in nature between colorless, yellow-golden, red, brown, blue, and green. Among consumers, blue is the most popular color of zircon. A CZ is usually created entirely colorless to make it diamond-like. But it can also be produced in different colors including yellow, pink, purple, green, and even multicolored.
Colorless natural zircon is considered the purest form of this mineral and if of high quality, it can be very rare. In fact, it is much rarer than diamonds but is still less valuable. So, a colorless natural zircon is obviously more expensive than lab-created cubic zirconia.
Swarovski Zirconia as in the picture is a perfected type of Cubic Zirconia. To the naked eye, it’s difficult to tell it apart from a real diamond but is still cheaper than diamonds (for sure) but not as much as the Swarovski crystals. Swarovski crystals are made of glass and are easily distinguishable from diamonds and are much cheaper
Spinel is a natural mineral that can be found in nature in many colors such as black, brown, blue, green, red, as well as white or colorless. This last one is extremely rare. Should you see a colorless spinel as a diamond simulant, it’s very likely synthetic. Exactly that colorless (or white) synthetic spinel is often used as a diamond simulant.
Regardless of color, spinel has a high refractive index which means excellent brilliance in a well-cut and polished stone. Also, spinel’s hardness of 7.5-8.0 on the Mohs scale makes it a nice choice for almost all jewelry pieces, including engagement rings. Spinel in engagement rings is a hard and durable gemstone and doesn’t require special care.
Glass & Rhinestones
A lot of materials can be called with the word “rhinestone”: from the high-grade Swarovski crystal to normal glass stones or inexpensive plastic stones like acrylic or resin ones.
But actually, the word “rhinestones” refers to small, sparkling natural quartz stones found in the Rhine River, Austria, in the 13th century. Over time, any equivalent diamond-like stones or materials were called rhinestones.
There are many kinds of rhinestones. There are glass rhinestones, crystal ones (when the lead oxide is added to glass), plastic, acrylic, and resin rhinestones. The most beloved rhinestone option for a diamond simulant is surely glass or in other words lead crystal.
The glass crystal is very affordable but actually, it isn’t a very good diamond alternative. It has a relatively low refractive index, which means that light goes right through it instead of being reflected back as brilliance. As a result, glass crystal has much less brilliance and sparkle than diamond. Today, glass crystal is only used to imitate diamond when the task is to make an imitation as affordable as possible.
Swarovski crystals, however, are made of extremely high-quality crystal glass. He created a very uniform structure of crystal which offers amazing clarity. That’s why it costs more than usual glass imitations, but the main reason for the high price of Swarovski crystals is a valuable brand name.
Natural rutile is one of three naturally occurring forms of titanium dioxide which can be found on the earth.
Natural rutile rarely has the clarity and color to serve as a diamond simulant. However, when synthetic rutile was created in a laboratory in the late 1940s, it had great optical properties for it: it is a bit more brilliant than diamond and has more than 7 times the fire of a diamond.
Besides, synthetic rutile can be made nearly colorless with excellent clarity. When it was first produced in the 1940s and 1950s, it was cut into gems and sold as a diamond simulant named “Titania”. Now it is not common on the market because it isn’t hard or scratch-resistant with only about 6 on the Mohs hardness scale, so it scratches fairly easily.
Other less common diamond simulants
Other colorless minerals, such as topaz, sapphire, and quartz, also some others, are rarely encountered today as diamond simulants. Some of them can be encountered only in vintage jewelry.
Colorless quartz was one of the earliest simulants of a diamond as well as rock crystal (a type of quartz). They are common minerals that people found in abundance in nature, and they are also colorless enough to appear especially well-formed, as faux diamonds.
Besides, quartz has an above-average hardness of 7–8 on the Mohs scale. The main point is that it shows less brilliance and fire. Nowadays it’s rarely used as a diamond simulant.
Synthetic Colorless Sapphire
For centuries, the best diamond alternative was the natural colorless (or white) sapphire. It has near the same brilliance, can be faceted just like a diamond, and is very durable. But a white sapphire is also a rare natural gem in its own right, it is hardly affordable as a diamond simulant for an average customer.
In the 1920s, synthetic sapphire was invented, making this diamond simulant more affordable and available. Today, white sapphire is offered as a diamond simulant by some laboratories and jewelry stores because it is harder and more scratch-resistant than a CZ. In addition, it keeps its whiteness and brilliance over time, whereas CZ is known to lose its color.
Strontium Titanate, YAG, and GGG
In the mid-20th century, many synthetic materials were invented in labs. One of them is a strontium titanate. It’s brilliant and has much more rainbow fire than diamond, which made it popular in the 1950-s and for the following decades. But it has a hardness only of 5.5, which is not only softer than a diamond but less resistant than most gems used in jewelry.
Starting in the 1970s, new lab-created diamond simulants such as YAG (yttrium aluminum garnet) and GGG (gadolinium gallium garnet) won the jewelry market for a short period. These simulants were more durable than strontium titanate. All three diamond simulants fell out of favor when CZ came to the market and nowadays you will very likely see them only in vintage jewelry.
Here is the chart summarizing all the written above. We hope it will help you to find your best diamond alternative.