I have got a whole bunch of these crystals.
The crystals are quartz. You can sell them but the value is dependent upon several factors:
- How large are the pieces? I can't tell from the photo
- Size and condition of the crystals affect price.
- Where are the crystals from? This is often the biggest factor into value.
- Can you Verify the location for the specimens?
If the quartz crystals from somewhere unusual (Tibet or Antarctica) or a famous mine /area, the value will be increased if you can provide some kind of verification.
- Are any of the crystals double-terminated?
- Are any of the crystals scepter crystals?
To get maximum value, you need to clean the specimens, and if you have the tools and patience, carefully trim the specimens as needed.
I use eBay as a loose guide for going prices on mineral specimens.
I believe they are quartz crystals and they don't have any other value other then they do look nice.
To have some value they need to be large (more then 100 grams) and crystal clear, and they also need to have a near perfect shape. Even then it is hard to get a good price.