These are handcrafted and available at ZensBlocks on Etsy. Cost $25.50 per set. The current sets available are made from walnut. The creator writes, "zenblocks. They are begging to be stacked, shuffled and contemplated. They require patience and practice, a clear mind and a steady hand. If you have none of those, they work just as well being banged around by a kid, but be prepared when the kid starts stacking them higher than you."
Other posts of interest:
©2011 Ashbee Design, Marji Roy