The Onyx Gemstone Necklace symbolizes the month of December. Details: The onyx stone measures 7mm wide and 10mm long. Made in Gold Fill and Sterling Silver. Every piece is tarnish resistant and hypoallergenic. Each piece from Falling for Dainty is handmade to order in our Santa Rosa Studio. Please allow for natural variations that may occur. Orders will ship in 3-5 business days via first class USPS.