Trapiche Amethyst teardrop in a fine silver setting with bead wire accent.  
18" Italian oxidized diamond cut rope chain 
Trapiche amethyst is a rare purple variety of quartz with a unique growth pattern that's said to have many meanings and healing properties: 
The name "trapiche" comes from the spokes of a milling wheel used to process sugar cane, which the stone's growth patterns and inclusions resemble.