Tip for emerald owners: clean your emeralds with a soft chamois or other cloth, using warm soapy water if needed. Do NOT use steam or an ultrasonic cleaner. Most emeralds are oiled and/or fracture filled and steam and ultrasonic cleaners can cause damage.
Brazilian emeralds are in demand for their stunning color and exceptional quality. http://gemstone.org/news/industry-news/277-brazilian-emeralds-rising-star-in-the-gemstone-world