The traditional material for yoga blocks is cork. Cork is light weight, but firm. While I usually use foam yoga blocks, cork yoga blocks have their uses.
Because of their greater weight compared to foam blocks, cork blocks add extra stability when doing a pose where you’re just a bit wobbly. They also compress less than foam blocks, so they are great to sit on when you need to elevate your hips.
These yoga blocks have rounded edges, making them easier to handle, and no logos or markings to wear off. I’ve had my blocks for several years now, and they are still in great shape. So, If you are looking for cork blocks to supplement your yoga practice, these are the ones I recommend.