C. 1990. Sometimes, serenity starts from the outside in. From our Estate collection, this beautiful .85 carat oval Swiss blue topaz pendant … C. 1990. Sometimes, serenity starts from the outside in. From our Estate collection, this beautiful .85 carat oval Swiss blue topaz pendant necklace shimmers with crisp, tranquil sparkle. Topped with a single round brilliant-cut diamond and set in polished 14kt yellow gold. Rope chain. Springring clasp, Swiss blue topaz pendant necklace. Exclusive, one-of-a-kind Estate Jewelry.