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 JewelHistory blog have been treated to her weekly (sometim… [read review or visit site]



Clubs & Associations

Other Great Reference Sites

Most watched eBay auctions    

Fine Vintage Victorian Revival 9k Gold Onyx Pearl Dangle EarringsModern Diamond 4.03ct Carnelian Onyx Gold Ring 6.9 Grams NrAntique Art Deco 14k Gold Onyx Pearl Lavalier PendantEmerald Onyx Diamond Lustrous Seed Pearl 9k Gold Long Ring NrArt Deco Czech Signed Brass Filigree Carved Coral Black Onyx Art Glass NecklaceVintage Chunky Men's Old Pawn Navajo Sterling Rick T. Onyx Inlay Ring Size 10Bold Vintage Mexico Sterling Silver & Onyx Link Bracelet | G AxVintage Esemco 14k Solid Gold Flip Ring,carved Shell Portrait Cameo,onyx,5 1/4Vtg 83g Bold Turquoise Black Onyx Taxco Mexico Mexican Sterling Silver BraceletFine Antique 14k Gold Victorian Earrings With Onyx And Pearl, No Reserve!Very Art Deco Platinum Top On 14k Gold Gen. Diamond Carved Onyx Mens CufflinksSigned Ham Alpaca Mexico Vintage Bracelet Carved Green Onyx Face Mask Unique W20Solid Gold Antique Agate & Onyx Special Swivel Fob Circa 1900Antique 14k White Gold Filigree Diamond Marquise Onyx Art Deco Ring Old 1920'sSuperb, Vintage Good Size Solid 9ct Gold & Onyx Agate Set Pinky / Signet RingC1890 Antique Victorian 10k Rose Gold Gf Double Sided Intaglio Photo Fob LocketEarly 1900’s 9ct Gold & Onyx Mens Ring. Unusual Hallmark !!!Vintage Navajo Sterling Silver Slave Bracelet Onyx Black Stone Indian HandmadeEdwardian Fine Filigree Diamond Platinum Top Gold Back Antique Circle PinVintage Jay King Dtr Onyx Turquoise NecklaceVintage Art Deco 14k White Gold Filigree Onyx & Diamond Mourning Ring Opens 10mm White Pearl Green Onyx Long Strand Necklace 191.4 Grams 30 Inch Long NrHeavy Vintage Old Pawn Navajo Eagle Black Onyx Sterling Mens Ring Sz 11Vintage Art Deco Sterling Silver Onyx Pearl Dice CufflinksLovely Art Deco Sterling Silver Marcasite & Black Onyx RingVintage Blood Red Coral Round Onyx Floral Sterling Silver 925 EarringsLot Of Antique Lockets And Pin Gold Plate Enameled With B&w Photos Onyx PearlVintage Antique Art Deco 10k Gold Onyx Ring Signed & Hallmarked Finger Size 7Beautiful~vintage~sterling Silver~onyx~graduated Bead NecklaceVintage Blood Red Carved Coral Onyx Sterling Silver 925 Pendant NecklaceAntique Pair Of Victorian 14k Solid Gold Onyx & Seed Pearl Mourning EarringsVintage Navajo Coral Onyx & Turquoise Heishi Indian Pendant Choker Necklace UsaCathedral Organ Victorian Necklace 1/20 12k Gold Filigree Black Onyx Sm. DiamondVintage Hattie Carnegie Onyx Glass Crystal Links Bracelet Goldtone Lead Free 6"lMexico Sterling Silver And Red Onyx Wide Cuff Bracelet 38 GramsVintage Estate Huge Gemstone Jewelry Lot Sterling Jade Onyx Pearl Amethyst +moreVintage Sterling Marcasite Onyx NecklaceVtg Handmade Zuni Sterling Inlay Bird Mop Turquoise Onyx Coarl Ring 7/8"x7/8"Vintage Deco Large Wide Solid Yellow Gold Black Onyx & Diamond Man's Estate RingVintage Art Deco Paste Channel Set Sterling Silver Bangle Bracelet Black Onyx Vintage 10k Solid White Gold Onyx Ring 2.9 Grams Size 7.5 No ReserveRlm Studio Robert Lee Morris Sterling Onyx 8-1/8” Bangle Bracelet 11.4gr NwotRare Ming's Hawaii 2 Strand Black Onyx Bead Necklace 14k White GoldVintage Sterling Ring Made By Niels Erik From, Denmark, No Reserve!Gorgeous Large Mens Art Deco 10k Gold Onyx & Diamond RingVintage 10k Yellow Gold Black Onyx Diamond Ring Size 6.25Antique 1940s Real 16ctw Black Onyx 925 Silver Bracelet Estate Hallmarked Silpada Sterling Silver Pendant Necklace Matte Black Onyx N1627 Circle Charm 9251940s Art Deco 10k Gold Black Onyx Men's Ring (vintage)David Yurman Designer Onyx Cable Bracelet 14k Yellow Gold & Sterling SilverVintage Navajo Men Ring Sterling Silver 27 Grams Turquoise Onyx Hand Made InlaidVintage Onyx Inlay Tassel Sterling Silver 925 Charm Pendant Locket (7.8g)Vintage Black Onyx Sterling Silver 925 Marcasite Necklace Gothic Dragonfly 16.5"Vintage 28" Necklace Native American Carved Turquoise Onyx Kachina Eagle W153Vintage Designer Joseph Esposito Espo Sig Amber Onyx 3 Stone Sterling RingDavid Yurman Designer Onyx & Diamond Albion Ring Sterling Silver 925 Size 6Fine Modernist Sterling Silver Onyx Collar Necklace Taxco Big 117 Grams VintagePeriod Art Deco Man's (or Unisex) Black Onyx In 10k Yellow Gold - Lovingly Worn!Stunning Vintage Crown Shape Cornelain, Onyx & Bloodstone Spinning 9 Ct Gold FobVtg Sterling Onyx Long=3=strand Beads Art Deco 2" Clasp Necklace Repair Findings