Clockwise, from top left: regular hook, stylish hook, push-pin/hook combo, suction cup hook, powder-coated plant hanger, wood plant-hanger (or an idea for an Ikea hack!). 

You can hang the Prisma not only from the ceiling, but you could also hang it from the wall right above your window, so the Prisma sits right in front of it. 

If your walls and ceiling are cement, then you're probably gonna have to go with screw hooks. There are the regular ones that you can get at any hardware store. And then there are more stylish options like this one

If your walls and ceiling are sheetrock, you can get away with using a push-pin! A regular push-pin right above the window will work great, or this push-pin/hook combo will work from the ceiling - be careful though, if you remove the push-pin from its spot once, you will have to insert it in a new spot. Otherwise it will be loose and might fall.

The Prismas also make a great effect on a wall, away from the window, where they get the direct light on them (direct light is key!). In that case, you'll want for it to be separated from the wall at least a few inches. That's where a wall bracket comes to play. This search on Etsy will give you plenty of options to purchase or ideas to diy yourself.

There is also the option of using suction cup hooks on the window. The largest crystal I use in some Prismas is pretty heavy so I'm not sure how well it will hold over time. I gave it a try and it worked for me, and it stayed put for a few months. May be worth a try! Just make sure that both the window and the suction piece are super clean.