In the early half of this decade, jewelry companies decided to bring black gemstones into their designs. Since then, both niche and mainstream buyers have been throwing cash at jewelers for their own chance at these pieces of edgy, contemporary jewelry. Not only was it a breath of fresh air to see gemstones like black diamonds set into dark metals, but it also allowed jewelry lovers a chance to get in touch with their inner wild child.

Thankfully, black gemstones are still popular, with many designers making them a central part of their collections and some buyers looking to use them as center stones for non-traditional engagement rings. So, let’s take a look at three of the most popular black gemstones and what to look for when buying them.

Black Onyx
Found in many countries around the world, including but not limited to Yemen, Uruguay, Argentina, Australia, Brazil, and the United States, black onyx is a banded variety of the oxide mineral chalcedony. While it was a popular stone in the gents’ pinky rings of the 70s and 80s, black onyx has been making a bit of a comeback as of late, showing up with fresh, faceted faces in pieces by designers like Ippolita and David Yurman.

The thing to remember when buying black onyx is that very rarely is the gem naturally black. Onyx comes in a variety of hues and artificial treatments have been used for ages to produce both the black color in black onyx and the reds and yellows in sardonyx. Most black onyx on the market today is not naturally black, but rather artificially enhanced to create a black appearance.

Black Spinel
With designers such as Misahara and Margo Morrison using black spinel in their highly-coveted jewelry pieces, the stone has risen in popularity and gained ground against other black gemstones. Like onyx, spinel comes in a variety of colors, but black spinel is often found in bead form as an accent to other dark hued gemstones or minerals like hematite or black pearls.

Black spinel is often faceted and looks luxurious when set in white metals, but can also look chic and modern when paired with high karat yellow gold.

Black Diamonds
Yes, black diamonds are still actual diamonds, but keep in mind that natural black diamonds with even color throughout are still a pretty rare find. Most black diamonds – particularly diamond melee (small diamonds used in design or to accentuate other stones) – have been treated in one way or another to enhance their color. The treatment process turns the natural diamond a greenish color that is so dark it appears black to the naked eye. In this decade alone, jewelry designers have used black diamonds as a contrast to white in designs that played off a “dark vs. light” feel.

Relatively inexpensive in comparison to their white diamond counterparts, black diamonds still need to be verified so that you, as the buyer, are sure that you get what you paid for. When shopping pieces containing black diamonds, make sure that you ask that the diamonds be tested to verify their authenticity, or have the piece appraised by an independent appraiser for your own peace of mind.