Cabochon

The Black Opal is considered the rarest and most expensive type of opal—particularly those stones that exhibit red and multicolored "fire." Compared to lighter-coloured stones, a high-quality natural opalcabochon with a dark body tone displays the "play of color" much more effectively, making it even more valuable and rarer in the market.

No, a cabochon is not a specific type of gemstone, but rather a cutting style designed to enhance the beauty of any gem, allowing it to display its allure in a truly exquisite manner. The cabochon cut features a smooth, polished, and rounded top paired with a flat back; this style is commonly applied to stones such as opals, turquoise, and moonstones to effectively highlight their unique patterns and colors.

However, a cabochon-cut stone can indeed be genuine—provided, of course, that you purchase it from an authentic and trusted source, such as Armonia Gems

Cabochons are not always so cheap; their price depends on the material. You can find many gemstone cabochons that are quite affordable because they require less cutting compared to faceted stones.

However, premium natural opal cabochons that exhibit a strong "play of color" can be highly valuable and rare, commanding a high price.

Speaking of the present time, it can be said that natural opal cabochons are definitely worth buying, as they are highly valuable—depending on their color, clarity, origin, and the play of fire they exhibit. 

High-quality opals—such as the Ethiopian Black Opals, which are considered premium—are in high demand; their price range extends from affordable levels to very high, collector-grade tiers.

The ideal size depends on the type of jewelry. For instance, in the case of rings, smaller opal cabochon stones (6–10 mm) are considered quite popular, whereas for pendants, slightly larger opal cabochons (10–20 mm) are used to showcase the stone's fire and color more effectively.

The price range for opal cabochons varies from $10 to over $500+, depending on quality, size, carat weight, origin, and the intensity of the play of fire. While you can find various common and affordable opal gemstones, some high-grade Ethiopian opal cabochons with their vibrant fire and superior clarity—command premium prices.