Opal VS Diamond – 5 Ways They’re Different & How To Choose Between Them

Opals and diamonds are two of the most fascinating gemstones, so it’s only natural to wonder how they would compare to one another. One gem offers the classic gemstone look, while the other offers a more… mysterious, magical look. Both gems are often featured in jewelry so you will find plenty of examples to look at. Now let’s compare opals to diamonds and see just how different (or similar) they are.

opal diamond

Opal vs diamond

Opals are far softer than diamonds, and as such they will easily scratch or chip. Opals require more care when being worn, compared to diamonds. A diamond will always shine and it also fetches a very high price tag, while an opal may lose its fire if mistreated and is far more affordable. That being said, a fine opal with great fire is harder to come by than a fine diamond.

Where a diamond gives you that classic, gemstone look with clarity, brilliance, and an impressive cut, an opal will impress with tis sudden flashes of color hidden within its unassuming body. Really, both opals and diamonds are very impressive gemstones, only they do this quite differently. Now let’s first take a refresher on what each gem is, before we go on to compare them.

What is a diamond ?

Diamonds are a type of solid carbon, and they are the hardest material known to man. On the Mohs scale of hardness, diamonds sore a10 out of 10, and cannot be scratched by anything other than a diamond. The most common diamonds you will see on the market are those that have a white or nearly white color, and good clarity. In truth diamonds are often yellow tinged, and sometimes appear light brown. There are also fancy color diamonds, meaning diamonds that show a distinct, saturated body color (pink, yellow, blue, green, etc).

What is an opal ?

Opals are a form of hydrated silica, and they do contain quite a bit of moisture (usually between 6-10%). It is the way the silica spheres are arranged and how closely they are packed together that gives opal its impressive color play (also called fire). The body color of opals ranges quite a lot, from white to cream to pink, blue, and eventually black. Not all of them show a play of color, as not all opals are the same.

Now let’s compare opals with diamonds, head on !

1. Diamond is much harder than opal

Right off the bat we have the question of durability, If you’re looking at jewelry chances are you want it to last quite a few years before you have to replace the gemstone (hopefully never). Well, a gemstone’s hardness rating will give you a good idea of what to expect.

Diamonds are the hardest material ever, scoring a 10 out of 10 on the Mohs hardness scale. They do no chip or scratch, unless hit with another diamond in which case the damage is mutual. This makes diamonds the perfect choice for everyday wear, and something that you can definitely pass down to future generations. Or, sell back to a jeweler if need be. Diamonds have amazing resale value.

Opals are much softer gemstones and they won’t survive as easily as diamonds. Opals have a Mohs rating of 6.5, which puts them under the 7 threshold. All gems above 7 are good to wear every day, but the lower the rating the easier it is to scratch them. So your opal, if you decide to get one, should not be a ring, or a bracelet as those get the most hits as you go about your day. Instead opt for a pair of earrings or a necklace, as they are much safer due to where you wear them on your body.

2. Opal sparkles on its own, diamonds need to be cut

Now let’s talk color and sparkle. The most common opal body color is white, but it’s never about the body color, it’s always about the fire in an opal. The fire is a true rainbow and it reflects all the possible colors and all of them bright. It’s the darker opals – blue and black – that manage to contrast the fire and make it stand out.

The fire can be small shards, patches, or a smattering of color as if someone spilled some glitter. Really, opals are mesmerizing. Their fire is best showcased in a cabochon cut, as it reveals a lot of the opal.

Diamonds usually come with a clear body color, or as close to clear as possible, such as a D grade on color. It’s the way a diamond is cut that brings about its brilliance and fire. A good cut takes advantage of a diamond’s high refractive index (2.42) and places the facets accordingly, so you get the maximum amount of sparkle. The best cut for a diamond is the round brilliant, as it was designed specifically with that refractive index in mind.

So both diamonds and opals sparkle, but do so differently. An opal can sparkle on its own but getting one that does this, and does it noticeably, is not easy. Diamonds sparkle once they are cut and they retain their sparkle throughout the ages.

Here’s an example of a beautiful, big opal necklace off Amazon.

This opal is fairly large, and has a shape resembling a triangle. The setting is a bezel, one of the most protective settings possible, made from 14k yellow gold, like the rest of the necklace. This is definitely a pendant that will draw compliments and it will last you for decades as you’ve very unlikely to get it scratched when worn this way.

3. Diamonds are clear, classic gemstones

The look you’re trying to achieve with the jewelry also matters. Do you want the classic gemstone look ? Something like a round cut, an emerald cut, something very sparkly ? The a diamond will offer that. It is clear, it is sparkly, and it will fit right into most people’s expectations of jewelry.

Opals are a bit different from the norm, in that they often require a different, more protective setting, and aren’t used in fine jewelry as much as diamonds. Does this mean opals are bad ? Not at all. They simply have a different look to them, one that may make you think of magic, mystery, something to ponder.

Diamonds impress on-sight, opals ask you to look closer.

4. Opals are much more affordable than diamonds

Price is a big factor when deciding what jewelry to get, and we all know this. It’s why lab grown diamonds have sprung up, and why many gemstones have a synthetic version as well. So let’s take a look at the most common price range for diamonds and opals.

An opal, a decent quality one, is usually around $45 carat. This is an opal that has a decent play of color and a white or cream body color. Darker opals fetch higher price because they have more contrast with the fire within an opal (around $2500 per carat). But, finding such an opal is not easy and it will usually be expensive. White opals with amazing fire are comparatively cheaper, going for 250-400 per carat.

Please keep in mind that opals are some of the hardest gems to price, as each opal is vastly different in appearance than the next. Opals are usually priced for their play of color, and this is heavily influenced by their body color and clarity.

Read also: Tourmaline VS Opal 

Now let’s look at diamonds. The highest clarity diamond (flawless) with the whitest color (D), and Ideal cut usually sells for about $25,000 per carat. That is eye watering but it is the most ideal version of a diamond, you literally cannot get a better diamond.

Now, most diamonds you find on engagement rings are less than that, as they have a bit of a yellow tint, a Good cut and not an Ideal one, and may be VVS1 instead of FL. Once you go for a slightly included diamond or allow a slight tint, the price drops dramatically.

For example a 1 ct diamonds with D color, Ideal cut, and VVS1 instead of FL sells $17,000. Keep the same specs, but change the color from D to H-G and you get $14,000 per carat. And again, keep the same specs but lower the cut to Very Good, and that same 1 carat now sells for $10,000. We’ve used (not sponsored) BlueNile’s diamond search tool, and opted for a brilliant round cut as that is the most common and sought after.

So in short, the most expensive opal will still be much cheaper than a low quality diamond, judging by price per carat. Here’s an example of a diamond tennis bracelet off Amazon.

This bracelet has a total carat weight of 3 carats, but you can customize it form 1.5 carats to 9, depending on how large you want the diamonds. The diamonds themselves are in the G-H color range, VS2-SI1 in clarity. The metal for the bracelet is 14k white gold, though it can be changed to yellow gold if you like.

5. Diamonds are easier to find that fine opals

Despite the prices you will find for a diamond, you stand a much better chance of finding a decent diamond with a decent price than a really impressive opal. Opals on their own are not hard to come by. But a fine quality opal with great fire ? Very difficult and you will have to pay quite a bit for it.

Meanwhile a diamond is easier to source, and if you’re looking for jewelry with multiple gems – like a gem bracelet or a choker – you need the gems to be as similar as possible. Diamonds make this mission much easier.

Can you wear diamond and opal together ?

Diamond and opal can be worn together as long as they are not in a ring or a bracelet. An opal will scratch while a diamond will not, so something more protective like a necklace or a pair of earrings would be more appropriate. One thing to note though, diamonds and opals will compete for your attention, so it’s best to scale down the diamonds and get a bigger opal instead.

Here’s an example of what we mean. An opal necklace with a diamond halo off Amazon.

The opal is a white opal, so it will not offer too much contrast but the fire is there. The diamonds are small, with a round cut, and they co all around the perimeter of the opal. The whole necklace is set in 14k white gold.

Is opal a good choice for an engagement ring ?

Opal is not the best choice for an engagement ring if you intend to wear it every day. Opals are soft, they will scratch and chip, and they are most often cut into cabochons. If you insist on an opal engagement ring we recommend you restrict it occasional wear, such as formal events or special occasions.

Keep opal away from moisture and daily wear. Excess moisture or just plain water will dull the fire within the opal. This is reversible, as the opal will regain its play of color once it has dried (about 48 hours). Keep opal safe as it will scratch, always take it off when performing house chores, woodworking, gardening, or something similar that may scratch the opal.