This is a pendant made with a dyed agate cabochon.  With the bail, it is approximately 57mm / 2.2 inches long.  
 
Agate is an excellent stone for rebalancing and harmonizing body, mind and spirit.  It cleanses and stabilises the aura, eliminating and transforming negativity.  Agate enhances mental function, improving concentration, perception and analytical abilities. 
 
The pendant will arrive in a small gift bag with an 18” waxed cord necklace.