The two rare gem collections, The Marcial de Gomar Emerald Collection and the Mountain Star Ruby Collection, along with more than 20 other loose emeralds, cut and rough, and 13 pieces of emerald jewellery will be live-auction lots through Guernsey’s, the New York-based auction house, with online bidding at liveauctioneers.com this spring.

Interested bidders can tune in and scoop up the emeralds on April 12, while ruby-seekers will have to wait until May 3.

The featured lots, collected by Manuel Marcial de Gomar, of the Marcial de Gomar Collection, include the Marcial de Gomar Star, the largest of only 11 star emeralds known to exist and the first known as a double-sided emerald; Tears of Fura, a large pair of teardrop-shaped Muzo emeralds; La Gloria, the largest Muzo rough emerald in North America weighing 887 carats.

On May 3, the Mountain Star Ruby Collection, a 343-tcw collection of four star rubies, will be up for auction, as well. This collection includes the 139-carat perfect six-ray Appalachian Star ruby. Since star rubies are generally found in areas of the world like Burma and Sri Lanka, the Mountain Star Ruby Collection’s North American origin makes it all the more rare.