Chitons are constantly scraping their teeth on rocks to eat the algae off of them, but that means their teeth need to be pretty tough. And it turns out one species's teeth are the hardest, stiffest biominerals in any living thing we've seen! Go to http://Brilliant.org/SciShow to try their Chemical Reactions course. Sign up now and get 20% off an annual Premium subscription. Hosted by: Hank Green SciShow is on TikTok! Check us out at https://www.tiktok.com/@scishow ---------- Support SciShow by becoming a patron on Patreon: https://www.patreon.com/scishow ---------- Huge thanks go to the following Patreon supporters for helping us keep SciShow free for everyone forever: Bryan Cloer, Chris Peters, Matt Curls, Kevin Bealer, Jeffrey Mckishen, Jacob, Christopher R Boucher, Nazara, charles george, Christoph Schwanke, Ash, Silas Emrys, Eric Jensen, Adam Brainard, Piya Shedden, Alex Hackman, James Knight, GrowingViolet, Sam Lutfi, Alisa Sherbow, Jason A Saslow, Dr. Melvin Sanicas, Melida Williams, Tom Mosner ---------- Looking for SciShow elsewhere on the internet? SciShow Tangents Podcast: http://www.scishowtangents.org/ Facebook: http://www.facebook.com/scishow Twitter: http://www.twitter.com/scishow Instagram: http://instagram.com/thescishow ---------- Sources: https://www.pnas.org/content/118/23/e2020160118 https://www.nature.com/articles/s41598-018-37839-2 https://news.northwestern.edu/stories/2021/05/rare-mineral-from-rocks-found-in-chiton-teeth/ https://news.ucr.edu/articles/2019/01/31/magnetic-teeth-hold-promise-materials-and-energy https://www.tandfonline.com/doi/abs/10.1080/00222933.2014.959574 https://www.materialstoday.com/biomaterials/articles/s136970211070016x/ Images: https://www.flickr.com/photos/47445767@N05/15947947127 https://www.istockphoto.com/photo/gumboot-chiton-gm183967843-27618844 https://www.flickr.com/photos/33466410@N00/3258676083 https://www.nature.com/articles/s41598-018-37839-2 https://www.flickr.com/photos/odfw/8020038038 https://commons.wikimedia.org/wiki/File:Santabarbaraite-270526.jpg https://www.researchgate.net/figure/Chiton-teeth-and-their-formation-A-Light-micrograph-of-the-radula-of-the-chiton_fig19_342396092 https://www.istockphoto.com/photo/gumboot-chiton-gm467679603-34055468