Glass and Mirrors - Glass shelving

I have very limited space in my room and im looking to get wall shelves. I'd like them to be made of glass even if they are a bit more expensive.

I've been shopping around for prices at local glass shops and due to my specific requirements most will need a day or two to get me an estimate. While i havent gotten any prices yet, some seem to recommend some wildly different sizes.

The shelves will mostly be used for books so they will need to be strong. Some recommend 3/8" thickness, some just 1/4", some recommend tempering, some don't. One company recommended safety glass instead of tempered. One company recommended 1/4" without tempering, which sounds dangerous, but assured me it was ok even for books.

I'm looking for more opinions on what should be a good size for glass shelving for books. While, im sure it would be great to have tempered 3/8", but i would rather not spend the money on it if i dont have to.

What might fellow DIYers recommend?

First of all we need the length and width and if it will be supported on 2 or 3 sides. This will help determine the glass thickness.

There are two pieces that are 36 X 10 next to each other to make it look as though it were 72 x 10. At one end it is 18 x 10 with a (single) 10 inch rounded corner. The other end meets the wall.

Two tiers will look like 90 x 10 with one end having a rounded corner.

Below the two tiers will be a few "floating" shelves made from two of the 18 x 10 (with the 10 inch rounded corner) next to each other to create a mini semicircle-ish 36 x 10 shelf.

There will be a wall bracket every 18 inches. Where two glass panels meet, the brackets will be 2 inches so each panel will get atleast 1 inch of support. The 36 x 10 pieces will have 3 supports. The 18 x 10 pieces will only have 2 supports, and one of the supports does not go to the edge entirely (due to the large rounded corner).

I can draw a picture if you would like more clarification.

From your description I have a pretty good picture of what you're doing. You are using brackets so that tells me that the back of the shelf will not be supported. I would recommend 3/8" glass (not tempered) since it will support all books. 1/4" tempered is 6 times stronger than non tempered and will be good if the weight wasn't from all books. Do not use 1/4" non tempered. All edges should be polished. Good luck with your project.