Most likely quartz. Can you tell us the location of the garden and can you take a clear photo looking straight down on the biggest prism. Then, count the sides on that and the others and report back.
How cool is that! Wonder if you'd find more if you dug around...have no idea what it is, but that's rather exciting to find something like that in your garden!!
How cool is that! Wonder if you'd find more if you dug around...have no idea what it is, but that's rather exciting to find something like that in your garden!!