The upper image is a 4 course block used as a garden ornament. It has a sand blasted finish.
The lower image is 3 course blocks used as interior walls of Alcorn Elementary School in Connecticut. The surround blocks are 8" x 8" x 4" CMU.
These photos show PYRIDIAM blocks used as border. They do not need to be cemented in place as their weight will keep them in place. They are particularly useful for controlling soil erosion as they will hold back dirt and debris yet let water pass thru between blocks. They are taller than Belgian block and again require no concrete installation.