Terrazzo is crushed-up stone and glass, held together by a binding agent. The countertop is then buffed for a nice smooth surface. You can color or stain the terrazzo for a custom finish and it's a pretty look, so you'll get lots of style points.
How green is it? If the product is made locally, you cut out transportation costs, which is important since terrazzo is heavy to transport. You can also use terrazzo made from recycled glass, in which case you eliminate the energy needed to obtain new stone or glass.
One disadvantage to watch out for is that the binding agents can sometimes release VOCs, volatile organic chemicals. These chemicals can potentially emit hazardous fumes into the air that can cause visual and respiratory issues. (One such chemical is formaldehyde) [source: Salant]. So, try to use a cement binder made from fly ash, a residue of burning coal. Fly ash would otherwise be landfill material, so using that type of cement binder eliminates the VOC issue and also recycles the fly ash.
Terrazzo is great because it has a long life span, but what happens after that? Unfortunately, it can't be recycled, so it ends up as waste. Weigh the green positives and negatives of terrazzo, but don't make any decisions until you read about some other options.