I have an opportunity to buy two beautiful fasceted stones from my sister. She got them at a gem and mineal show in Denver. She was told they they are from Afghanistan and that they are bi-chromic Sapphires, but have never seen anything like them. They are purple in incandescent light and a lighter blue in sunlight. In blacklight they are almost clear. The red stripe in the smaller stone (1/2) really stands out. The larger stone (3.5ct) has several red stripes. They are supposedly cut from the same rough stone. Any idea what these stones are? I think they''re pretty to look at, but have no idea what they''re worth. She paid $300 for both. ANy guesses would be appreciated. I am a collector of tourmaline and natural crystals, but have never gotten into the cut precious/semiprecious stones. See the picture I attached. Thanks and have a good day.