The only four precious stones are the Big 4 – diamonds, sapphires, rubies, and emeralds. Then, High-Value Semi-Precious Gemstones consist of gems like tanzanites, opals, pink sapphires and ...

Throughout history, gemstones have been symbols ... carat for top-quality specimens. While sapphires are typically associated with a deep blue hue, the pink and padparadscha varieties (a delicate ...