I just recently purchased a tear drop design needlepoint turquoise necklace and earring sterling silver set. The necklace has a stamp FB. The earrings do not. I thought I paid a lot for it ($200+) but after researching online I have found true turquoise to be quite expensive. I am wondering if I bought imitation turquoise? The stones are a light color with what looks like gold veins. If it is stamped FB which after some research stands for Fred Baca could it possibly be a fake?