Ma'am
If you use decorative rocks as an aggreget and run water over your completed job, the stone will be exposed. I don't know of any links I can send to you, and wouldnt be able to send them to you due to my lack of computer skills. If you look for tumbled rock or polished stones as an aggreget on the internet you'll find alot of neat ideas.
We had a teacher that wanted custom steppers in her Obama grant garden. We never get premixed concrete, so I went to our local sand & gravel Co. and found reasonably priced tumbled rock and used that for our aggreget, using a stepper form purchased a long time ago, we filled it then ran a slow but steady stream of water over it to remove the top cream. What was left behind was the aggreget that was about 1/4 of an inch above the rest of the form. It looked so nice that someone stole them! I took it as a complement.