Without further ado, let’s quickly open your eyes to some mind-blowing necklace designs. Floral Necklace Well, the first on our list of top 5 blue tanzanite necklace ideas is the floral design. Because of the thing of beauty that tanzanite is, no other design can ever best portray the gemstone’s brilliance & fire than the floral design. As the name suggests, in this type of design, the tanzanite centerstone of the necklace sits in the middle of a flowery setting.