Where did you get them? They seem to be very pure. Did you buy them? If you found them, where did you find them? I think they are beautiful specimens.
I would not speculate without more info.
Can you scratch the spacimens with your fingernail, a regular nail, a piece of quartz?
I can see they are translucent. If you shine a light on them, do either one of them flouresce, (glow in the dark)?