Firstly great work, and welcome to BGG.
You could use a soft box (some lighting) overhead or of to the side. this will help create some shadows. But it needs to be soft, if the light source is to powerful it will lesson the bright crystal objects that you are photography.
Also in my opinion you could use a higher f.stop this will increase depth of field. bringing more of the pieces into focus.
Second one down is my favourite.
I like the softbox approach. Will do. Will give the f-stop some adjustment this next try. Thanks Gary