Turquoise is among the oldest known gemstones.  It has been mined since 3,200 BC and graced the necks of Egyptian Pharaohs and adorned the ceremonial dress of early Native Americans. A porous gemstone, turquoise can absorb anything it touches. 
Zircon is an underrated gem that’s often confused with synthetic cubic zirconia due to its similar name and shared use as diamond simulants. 
Tanzanite is one of three modern December birthstones. A relatively recent addition, tanzanite joined the modern birthstone list in 2002. It was the first major change to the modern birthstone list since 1952. Compared to zircon and turquoise, a tanzanite birthstone is a perfect gift for someone who prefers a moodier, more mysterious birthstone.    Tanzanite jewelry is also the traditional gift for the 24th wedding anniversary.