Are Opals Precious or Semiprecious Gemstones?

Are Opals Precious or Semiprecious GemstonesOpals are arguably one of the loveliest gemstones in the world. With their fiery iridescence and vibrant patterns, opals beautifully accentuate jewelry. Hailing from several corners of the earth — from the Australian outback to the hills of Ethiopia — opals offer gemstone and jewelry enthusiasts the chance to truly behold a one-of-a-kind gem.

Despite their universal appeal, a glance at this striking gem’s background can raise a few questions. First, are opals precious or semiprecious gemstones? And on that note, does this classification relate to opal value?

We’re tackling that important question, and outlining the key difference between precious and semiprecious gemstones. Keep reading to find out which category opals fall into!

The Confusion About Precious Vs. Semiprecious Gemstones

Gemstones, minerals, and rocks commonly fashioned into jewelry fall into two categories: precious or semiprecious gemstones. Since around the 1800s, this classification has helped to differentiate one gem from another. However, the actual categorization process is complex, as there are now many different criteria to consider. Overall, this leads to misrepresentation and portrayal of certain gemstones.

For the most part, a gemstone’s quality and rarity are two factors considered during the classification process. Times have changed since the initial introduction of these processes with the discovery of new and unique variations of gemstones. As such, market values and prices have fluctuated over the years. Ultimately, classifying gems between semiprecious and precious has become slightly puzzling.

It’s important to note that there are certain gemstones that are at times considered precious, and other times considered semiprecious. There are also certain varieties of the same stone (like beryl) that fall into both categories. Confused? Don’t worry, we’ll mine the details of how to differentiate and understand precious vs. semiprecious gemstones.

What Are Precious Gemstones?

Before we answer if opals are precious or semiprecious gemstones, let’s discuss what these terms actually mean.

Precious gemstones

are typically more expensive and sought after than semiprecious gemstones, however, this is not always the case. Generally, there are four gemstones qualified as “precious” and they are as follows:

Although these four precious gemstones are the most popular in this category, there are a variety of others as well. In some cases, gemstones that qualify as semiprecious are considered precious. For example, you may occasionally see pearls, jades, or even opals considered as precious gems. However, this is uncommon as these gems are typically considered semiprecious.

Why is that? Well, it boils down to the unique qualities of the gemstone that make the classification process so complex. As a rule of thumb, diamonds, rubies, emeralds, and sapphires are the most common precious gems. So, while you may see opals occasionally marked as precious, remember that they are most often classified as semiprecious. Let’s find out why.

Why Opals Are Semiprecious Gemstones

While we’ve mentioned that opals can sometimes be considered precious, these lovely gems are more often considered semiprecious. And they aren’t the only semiprecious stones!

What are semiprecious gemstones?

Aside from the four gemstones mentioned above, almost all other gems are considered semiprecious. Other than opals, you’ll find that gemstones like amethyst, aquamarine, lapis lazuli, moonstone, pearl, and rose quartz are classified as semiprecious — and these are only the more common stones! There are so many other semiprecious stones, all equally as lovely as the traditionally more expensive precious types.
Are Opals Precious or Semiprecious Gemstones

When the gemstone and jewelry industry first started categorizing gems as either precious or semiprecious, it was mainly a way to distinguish the main four precious gems from the rest. At this time, these four gems were more expensive, rarer, and more sought after. However, if we’ve learned anything from the gemstone industry, it’s that times change and so do the markers for valuable gemstones.

There may be more semiprecious gems such as opal, but that doesn’t mean they are any less lovely, expensive, or rare than precious stones. Opals are an excellent example of this concept. You can find lower-priced opals on the market, but you can also find incredibly lovely, rare, and expensive opals!

So, while opals are sometimes classified as precious, they are definitely mostly considered semiprecious gemstones. But, as every opal lover knows, this doesn’t mean they are any less “precious”!

What Makes Gemstones Precious or Semiprecious?

Now that we understand the common gemstones that fall under the precious and semiprecious categories, let’s try and narrow down why these stones are categorized in this way. It’s a bit confusing at times, isn’t it?

While there are some gems that can be classified as both types (such as opals), most gemstones are semiprecious. Only diamonds, rubies, emeralds, and sapphires are only ever considered precious — and these gems also tend to be more expensive, traditionally. It’s confusing that certain gems can be found under both types occasionally, and this tends to happen simply because the classification process lacks hard-and-fast regulations.

As mentioned above, gemstones are classified by their rarity and quality. This is why you may see some fluctuation in how certain gems are categorized. Plus, while precious gemstones do tend to be more expensive than semiprecious, this isn’t actually the case all the time.

You can find that some semiprecious stones are more expensive than precious ones on the market. The same applies to the rarity of a gemstone. For example, you can have a less expensive diamond, which is considered precious, and a rare opal that’s considered semiprecious. In this case, the semiprecious opal might actually be more valuable than the diamond, despite its classification.

As a general rule, excluding diamonds, rubies, emeralds and sapphires, almost all gemstones are semiprecious. It truly is as simple as that!

Does it Matter if Opals Are Precious or Semiprecious?

In truth, many industry leaders regard this classification system as outdated and arbitrary. Not only is the whole semiprecious vs. precious categorization confusing, but it’s not entirely accurate when depicting a gemstone’s value. The gemstone classification process isn’t grounded in any scientific data, so it’s easy to feel puzzled when trying to distinguish between the two.

Furthermore, there are much more reliable ways to value opals, including by origin, gemstone family, chemical structure, and popularity.

Price and rarity aren’t the primary factors when analyzing what makes a gemstone desirable or beautiful. When the classification system first rolled out, precious gems traditionally equaled pricier, more valuable gemstones. Now, this logic doesn’t hold up considering the vast array of jewels in the market.

Bottom line: you should buy a gemstone based on your personal taste and desire, not the way it’s classified. Because when you get right down to it, precious or semiprecious, opals truly are one of the most spectacular natural treasures in the world. And in that way, they are all truly precious!


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One thing that stands out to me is that the hardness of precious gems like ruby and diamonds is quite high on the mohs scale. Aside from the natural beauty of the gems, it could indicate that the precious gems have more durability and may survive untarnished for generations.

On the other hand, it seems to me that some opals are particularly susceptible to cracking or other negative outcomes due to the water content and other minerals. This could be a factor in the valuation and designation of precious vs semi-precious.

I do still think opals are stunningly beautiful and precious to many people though. I hope my opals last a lifetime.

5th Apr 2020

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