The movement of ions or molecules across a cell membrane in the direction opposite that of diffusion, that is, from an area of lower concentration to one of higher concentration. The energy needed for active transport is supplied by ATP.
At the second tier, you can expect to pay $60 - $70 per linear foot. You'll have some concerns about chipping and denting, but less so than at the lower tier. At the highest tier, soapstone bathroom countertops are priced at $70 - $80 per linear foot, and their durability should not be an issue. See also: Bathroom Remodeling Ideas, Options and Solutions.
Soapstone has been used for centuries as a countertop, and its popularity endures, as do the countertops themselves: soapstone fans swear by their durability. These slabs of stability don't come cheap, though, and while prices vary, you'll likely be looking at upwards of $80 per square foot.