Hi FIl,
I think this file shows what you were asking. I created a second circle that is the exact diameter of the gem, to have it be end to end like in your first example. If you use the larger one, there will be space between the gems. With the larger circle in the original sample file, I also created a duplicate circle there. So if you want to select both of those circles and run the ArrayGem Command on them, you can see the 2d objects created with a "0 spacing" set.