Thank you so much for doing the research and sharing, @christina4! I don’t have any in my current collection, but I’ll keep an eye out for Satin Spar/Selentie mix-ups in the future. Thanks for brining this to attention! 
I totally agree. It’s one thing if you buy it from a source that doesn’t claim to be reliable- like a yard sale or given by a friend. But if the shop advertises it as one type of crystal- it really should be what they claim it is!
I know the feeling, @jill! I asked for some recommendations a while back and got some good and reputable places to buy crystals online- you may be interested in checking out some of the shops that everyone shared! 
Happy crystal shopping! 
