Here's another craft I HAD to try, since I have so many regular cats eye marbles that are my least favourite, and therefore can be pressed into service for craft purposes.
I used a roll of duct tape in the center to keep the marbles upright. It was my intent to do a 4th row but there was a design issue in the 3rd row that precluded me from going any taller. While marbles may look like the same size, I ran into a few difficulties because they aren't.
Glitter candle for illustrative purposes only; a plain candle of any colour would look better.
The glass part of this flicker candle broke, but I kept the metal design inner part.
A small, and square, jar of beach glass even fits into it! You could even put marbles in a jar.
I used E6000 glue, which can be seen in between the marbles if you look close, but I was pleased with it's holding power. This project was a definite win.