Thank you everyone for all of your input!! If it helps, this is what I am trying to make as the final block:
http://www.quiltingboard.com/t-141590-1.htm. With this question (post), I'm focusing on the middle "diamond." I took a 4 7/8 square of the light green, made a half square triangle, and did the same for the dark green...then sewed them together to make the middle diamond! I've been thinking about this for over an hour. My head hurts. :)