Like agate, onyx is a type of chalcedony, which is a cryptocrystalline quartz. The key difference between the two stones is that the characteristic bands we admire in agates are curved, while those in onyx are straight, usually alternating between black and white or brown and white.

Onyx is a favorite material for cameo makers, who will frequently carve into, say, a white layer until they’ve removed enough of it to reveal the black layer below. In this case, the result is a white image that appears to float on an inky background. Onyx is also cut into beads for necklaces, teardrops or geometric shapes for earrings, and bold cabochons for rings.

Also like agate, onyx is easy to dye. The recipe calls for boiling the stone in a sugar solution, then letting it steep in sulphuric acid. When the acid hits the sugar, black carbon is created, which seeps into the stone. This technique is used a lot because the demand for black onyx far outstrips the supply. In fact, dyed black onyx was used liberally during the Art Deco era, when dramatic contrasts and hard edges were all the rage.


Best of the Web (“Hall of Fame”)

All About Jewels Dictionary

All About Jewels Dictionary

This incredible reference dictionary on jewelry, from Enchantedlearning.com, is both beautiful and comprehensive. S… [read review or visit site]

Morning Glory Antiques and Jewelry

Morning Glory Antiques and Jewelry

Jewelry collectors, feast your eyes on this internet gem! It's a goldmine of jewelry information featuring all styl… [read review or visit site]

Cathy Gordon's Jewelry Gallery

Cathy Gordon's Jewelry Gallery

With its vast galleries featuring clear images of jewelry and style, this site really covers it all! Divided up by … [read review or visit site]

Jewel History

Jewel History

Since March of 2007, readers of Lori Ettlinger Gross’s Jewel History blog have been treated to her weekly (someti… [read review or visit site]



Clubs & Associations

Other Great Reference Sites

Most watched eBay auctions    

18ct/ 18k Gold Onyx & Ruby Art Deco Design Designer Stud Earrings, 75014ct/ 14k Gold Diamond & Onyx Art Deco Cluster Ring, 585Vintage Diamond 3.92ct Emerald Onyx 18k Gold Wide Ring 16.4 Grams Nr18ct/ 18k Gold Onyx & Seed Pearl Art Deco Earrings, 750Vintage Diamond Onyx 18k White Gold Drop Earrings 11.0 Grams Nr10k Solid Gold Mens Top Quality Vintage Black Onyx & Diamond Nugget Ring Sz 10Sterling Silver 925 Vintage Expansion Bracelet 36 Grams Marcasite Onyx Deco C404Art Deco Estate Sterling Silver Genuine Onyx Ring Size 8 No Reserve 925Vtg Givenchy Paris Couture Deco Coral Onyx Crystal Huge Sautoir Runway Necklace Antique Victorian Sterling Silver Black Onyx & Pearl Mourning Pendant NecklaceLagos Caviar Large Estate Onyx Sterling Silver Ladies Ring Sz 7.5 No Reserve!!Ladies Elegant Vtg 14k Solid Yellow Gold Black Onyx Bead Necklace 30" Long WerSterling Silver Lapis Aventurine Onyx Clunky Multi Color Vintage BraceletMens 1940s Vintage 10k Yellow Gold Single Cut Diamond And Black Onyx Ring10k Solid Gold Top Quality Antique Victorian Black Onyx & Diamond Ring Sz 8.5Vtg Mexico 950 Silver Onyx Bowtie Hinged Panel Necklace Earrings 86 Grams TaxcoGorgeous Vintage Carol Felley Navajo Sterling & Onyx Cuff Bracelet Black Onyx Diamond 14k White Yellow Gold Art Deco Vintage Mens RingS Antique Victorian Gold Filled Mourning Pin Jet Onyx With Earrings Center Stone10k Solid Gold Mens Heavy Top Quality Vintage Black Onyx & Diamond Ring Sz 9.7510k Solid Rose Gold Black Onyx Victorian Mourning Ring Small Size 3+ 3g No ScrapVtg Sterling Silver Zuni Turquoise Coral Mop Onyx Inlay Ring Mens Size 11 11.2gmVtg Mexico 950 Silver Onyx Bowtie Hinged Panel Link Bracelet 34 Grams TaxcoSterling Silver 925 Vintage Bracelet 28 Grams Green Onyx Gemstones C402Ortak Sterling Silver 925 And Onyx Celtic Knot Droplet Earrings Stud Pierced Estate Diamond Onyx Pearl Star 9k Gold Oval Ring NrSterling Silver - Antique Floral Green Onyx 5g - Ring (6.5) Cw6153Vintage Sterling Silver - Navajo Turquoise & Onyx Tear Drop 6g - Dangle EarringsBeautiful Antique Art Deco;coral & Black Onyx Gemstones Set Sterling Silver RingVintage Onyx Pearl Fleur De Lis 9k Gold Long Oval Ring NrVintage Mexico 925 Sterling Silver Carved Green Onyx Mask Bracelet | G AoVintage Sterling Silver - Zuni Signed Onyx & Opal Inlay 5g - Dangle EarringsBeautiful Turquoise Onyx Malachite Inlay Vintage Navajo Ring Sterling Silver ...Victorian 12k Gf Italian Micro Mosaic Onyx Floral Lavaliere Necklace Pendant-wowFine Vtg Zuni Indian Sterling Silver Turquoise Onyx Coral Inlay Drop EarringsEstate Onyx 14k Gold Necklace Pendant 5.0 Grams NrBvlgari Bulgari 18k Gold Onyx Disc Necklace Vtg Sterling Silver - Southwestern Onyx Dakota West Ring Mens Size 9.5 - 13.5gAntique Art Deco 10k Solid Gold & Black Onyx Size 6 Ladies Flapper Ring 1.5 GramErenst Wood Navajo Sterling Silver Onyx Oyster Shell Turquoise Bear Necklace | JVtg 80s Berrera Couture Mogul Onyx Pearl Byzantine Maltese Cross Gilded EarringsAcleoni Designer Signed Sterling Bezel Set Black Onyx Tennis Estate Bracelet 20gVintage Estate Sterl Silv Signed 925 Onyx Mop Marcasite Cameo Necklace!!! G6954Vintage Sterling Silver - Zuni Onyx & Mop Dangle 2.6g - Post Earrings Ct5123Vintage Gold Filled Necklace Pendant Choker Amethyst Onyx Bead Multi Strand C480Vintage Sterling Silver - Zuni Coral Onyx J-hoop 3.2g - Post Earrings Cu2023Antique Loyal Order Of Moose Pap 10k Yellow Gold Onyx Ring 7.75 Gram Sz 12 LoomVictorian Gold Fill Carnelian Sardonyx White Onyx Rider Horse Fob Charm PendantVintage Sterling Silver - Navajo Signed Onyx Cabochon 15g - Ring (11.75) MensVintage Jewellery Sterling Silver & Onyx Art Deco Style Brooch PinVintage Sterling Silver 925 Black Onyx Dangle Mexico Ladies Earrings 14.2g10k Solid Gold Mens Top Quality Vintage Black Onyx Ring Sz 10.5 Awesome FindLadies Fine Opera Length 14k Yellow Gold Black Onyx Bead Necklace 34" Long WerSterling Silver 925 Vintage Clamper Bracelet 19 Grams Marcasite Onyx Small C403Vtg Egyptian Revival Onyx Tigers Eye Jasper Scarab Bug Bracelet Hiquality C102Vintage Sterling Silver - Navajo Black Onyx Cabochon 9.7g - Ring (6.75) Cs7513Western Sterling Silver Big Chunky Old Pawn Onyx Carved Cameo Bracelet Vintage Sterling Silver - Navajo Leaves Onyx 15.8g - Clip-on Earrings Cu1683Vintage Sterling Silver - Kabana Scroll Black Onyx 4g - Ring (7) Cq9013Mens Ruby Diamond Gold 10k Onyx Vintage Retro Deco Size 8.50 Band Ring