Hello, it might help if you mentioned what kind of sample this is?

It seems an image 40X in phase contast o: I have the impression to see a slight green colour. I suggest you to do the same obersvation in bright field, 40X (excluding the phase ring),ose are photosintetic micro-organism, such as Algae. There are nice pictures of such organisms in APHA Standard Methods, and according the dimensions, you can go in the direction of indentification (that will require additional efforts)

Could you please let me know what were you trying to find out from which material. Apparently it looks like some crystals.

Those appear to be diatoms, but they are very large for 40x. 

It seems like a microalgae.