These genuine Onyx gemstones look amazing in luxurious, detailed crown settings!  The gemstones are lightly faceted for a lot of extra shine and flash. Shown here in Gold Plate and also available in other finishes. 

Stone Size: 18x13mm / .70 inches / 1.8cm each
Stone Material: Genuine Onyx Gemstones
Settings: Heavy cast Brass with your choice of plating (Gold plate is shown), offset loops to prevent the settings from flipping around and showing the back. 
Length: 16" (40.6cm) with a 2" extender chain for flexible sizing

Matching earrings available here:

18x13mm necklace, oval necklace, orange topaz brown yellow