14K Yellow & White Gold Purple Stone (Tanzanite?) & Diamond Ring THL Approx 7

14K Yellow & White Gold Purple Stone (Tanzanite?) & Diamond Ring. This is Somewhere around a size 7 (maybe a bit smaller or larger). It didn’t sit well on my ring size tool so my pictures just show an estimate of rough sizing. I bought this many years ago new and was told it was tanzanite and diamonds but I never had it appraised so I can’t be positive that they are indeed real stones. It is marked 14K and I believe THL inside the band but I may be reading it wrong. This is a beautiful ring but it is too large for me so I don’t wear it very much. It is in used condition and shows all over wear and has scratches, dents and may have other imperfections since it isn’t new and has been worn/ used. Colors may be off because of lighting. Please ask questions.