Turquoise and Tanzanite are the birthstones for the month of December. Known for its striking blue-green hue, turquoise is symbolic of peace, luck and protection. Turquoise also makes an ideal gift for an 11th wedding anniversary. Tanzanite gemstones have an exquisite indigo-blue, violet hue and are associated with good luck and new beginnings. Tanzanite jewellery also makes an ideal gift for a twelfth wedding anniversary.