Task: Text Simplification
Input (English): obsidian has been used in cardiac surgery , as well-crafted obsidian blades have a cutting edge many times sharper than high-quality steel surgical scalpels , with the edge of the blade being only about 3 nanometres wide.
Output (English): obsidian has been used in cardiac surgery because they are sharper than surgical steel scalpels , and contain a blade about 3 nanometres wide.