It's not recommended. The joints will crack in a few years.
We've heard of people doing it, so if you do, compact the sand or your base as much as possible. That will stop some of the shifting.
You should look at some products like polymeric sand or breeze with a stabilizer to fill in your joints. They will shift with the stone and give you color in the joints.
Talk to your local stoneyard about those two options and I bet they'll have them.
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