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Octagon Buff Top Double Bevel Genuine Black Onyx

Part # 947-F21 Only 2 left Weight -- lb -- g
Current price $3.48
Volume pricing
Total qty Discount Per unit You save
1 – 2 $3.48
3 – 4 5% off $3.31 $0.17
5 – 9 10% off $3.13 $0.35
10 + 12% off $3.06 $0.42
Add 2 more for 5% off, saves another $0.17 each.
Select Size: 9x7mm

Black Onyx, also known as black agate, is dyed black chalcedony. Chalcedony is composed of microscopic quartz crystals not visible to the naked eye. Natural black chalcedony is exceptionally rare — virtually all black chalcedony on the market is grey chalcedony that has been chemically treated to achieve its characteristic deep, uniform black color. Black Onyx is the top-selling chalcedony in the jewelry trade and has a rich history of use in Art Deco jewelry design.

These genuine black onyx cabochons feature an octagon buff top double bevel cut, offering a refined profile well suited to rings, pendants, brooches, and other fine jewelry settings. Each stone displays a consistent opaque black appearance, making them ideal for matched sets or coordinated designs.

Clean with warm, soapy water. Use of ultrasonic and steam cleaners is generally considered safe for these stones.

Features

  • Genuine black onyx (dyed black chalcedony)
  • Octagon buff top double bevel cut
  • Uniform opaque black color throughout
  • Chemically dyed treatment for consistent, rich black appearance
  • Safe for ultrasonic and steam cleaning
  • Suitable for rings, pendants, brooches, and other fine jewelry applications

Specifications

Stone Type Genuine Black Onyx (Black Chalcedony)
Cut Octagon Buff Top Double Bevel
Treatment Dyed
Transparency Opaque
Color Uniform black
Cleaning Warm soapy water; ultrasonic and steam generally safe

Available Options

Part # Size
947-F21 9x7mm
947-F22 12x10mm
947-F23 14x12mm
947-F24 16x12mm
California Prop 65 Warning California Prop 65 Warning:
Cancer and Reproductive Harm. www.P65warnings.ca.gov.
Brand
Otto Frei
Part #
947-F21
Type
Cabochon
Dimensions
0.1 in x 0.1 in x 0.1 in
Stone Type
Genuine Black Onyx (Black Chalcedony)
Cut
Octagon Buff Top Double Bevel
Treatment
Dyed
Transparency
Opaque
Color
Uniform black
Cleaning
Warm soapy water; ultrasonic and steam generally safe