Why the Hardest Rocks Can Be Easy to Break

So, rocks are hard. But the scale we use to rank them, the Mohs scale, is only really good at quantifying that for one kind of hardness, and topaz is a perfect stone to talk about to explain that. And you can check it out in our SciShow Rocks Box subscription! Hosted by: Stefan Chin (he/him) ---------- 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: Adam Brainard, Alex Hackman, Ash, Benjamin Carleski, Bryan Cloer, charles george, Chris Mackey, Chris Peters, Christoph Schwanke, Christopher R Boucher, DrakoEsper, Eric Jensen, Friso, Garrett Galloway, Harrison Mills, J. Copen, Jaap Westera, Jason A Saslow, Jeffrey Mckishen, Jeremy Mattern, Kenny Wilson, Kevin Bealer, Kevin Knupp, Lyndsay Brown, Matt Curls, Michelle Dove, Piya Shedden, Rizwan Kassim, Sam Lutfi ---------- Looking for SciShow elsewhere on the internet? SciShow Tangents Podcast: https://scishow-tangents.simplecast.com/ TikTok: https://www.tiktok.com/@scishow Twitter: http://www.twitter.com/scishow Instagram: http://instagram.com/thescishow Facebook: http://www.facebook.com/scishow #SciShow #science #education #learning #complexly ---------- Sources: Mohs Hardness Scale (U.S. National Park Service). https://ballarini.cive.uh.edu/wp-content/uploads/2016/06/96.pdf Topaz | Geoscience Australia Cleavage of Minerals | Geology In https://www.tandfonline.com/doi/abs/10.5408/1089-9995-55.1.56 The Largest Faceted Gemstones in the World | Geology In Moh's hardness scale compared to indentation hardness https://www.chemeurope.com/en/encyclopedia/Indentation_hardness.html http://www.minsocam.org/ammin/AM21/AM21_75.pdf https://www.palagems.com/topaz-buying-guide https://www.langantiques.com/university/beryl-2/ https://www.gemsociety.org/article/topaz-jewelry-and-gemstone-information/ https://www.ga.gov.au/education/minerals-energy/australian-mineral-facts/sapphire Image Sources: https://www.gettyimages.com/detail/video/mans-hand-with-a-hammer-hits-the-rock-stock-footage/1989724380 https://commons.wikimedia.org/wiki/File:Mohs.jpg https://www.gettyimages.com/detail/photo/large-lunulae-or-half-moon-at-fingernail-with-royalty-free-image/1449865087?phrase=fingernail https://www.gettyimages.com/detail/photo/nail-on-white-royalty-free-image/183295634?phrase=nail https://www.gettyimages.com/detail/video/diamond-loose-image-loopable-stock-footage/473169193 https://www.gettyimages.com/detail/video/natural-ruby-gemstone-on-the-turning-table-stock-footage/1314826038 https://www.gettyimages.com/detail/photo/blue-sapphir-on-black-coal-background-royalty-free-image/1222335712?phrase=sapphire https://www.gettyimages.com/detail/photo/uncut-imperial-topaz-royalty-free-image/535427664?phrase=topaz https://www.gettyimages.com/detail/photo/macro-mineral-spinel-stone-on-white-background-royalty-free-image/1079170642?phrase=spinel https://www.gettyimages.com/detail/photo/searching-for-stones-mines-and-precious-crystals-in-royalty-free-image/1054936628?phrase=spinel https://www.gettyimages.com/detail/photo/topaz-nestled-in-bedrock-from-mexico-royalty-free-image/1724251277?phrase=topaz+mine https://commons.wikimedia.org/wiki/File:Topaz_27.jpg https://commons.wikimedia.org/wiki/File:Topaz_NHMLA.png https://commons.wikimedia.org/wiki/File:Topaze_Brésil.jpg https://commons.wikimedia.org/wiki/File:Topaz_red.jpg https://commons.wikimedia.org/wiki/File:Topaz-170679.jpg https://www.gettyimages.com/detail/photo/rough-green-beryl-gemstone-isolated-royalty-free-image/1247698990?phrase=beryl https://opentextbc.ca/physicalgeology2ed/chapter/2-6-mineral-properties/ https://www.nature.com/articles/s41524-021-00608-3 https://commons.wikimedia.org/wiki/File:Cleavage_planes.png https://www.gettyimages.com/detail/video/topaz-mineral-stone-sample-in-rotation-with-white-stock-footage/1090929656 https://www.gettyimages.com/detail/photo/microscope-rock-analysis-royalty-free-image/531323408?phrase=geology+lab https://www.gettyimages.com/detail/photo/diamond-head-pin-and-adjustment-move-up-down-table-royalty-free-image/1339874377?phrase=vickers+test https://www.gettyimages.com/detail/photo/macro-stone-mineral-yellow-topaz-on-a-black-royalty-free-image/1327598545?phrase=topaz https://www.gettyimages.com/detail/photo/pure-quartz-crystal-cluster-on-black-background-royalty-free-image/1446932434?phrase=quartz https://www.gettyimages.com/detail/photo/imperial-topz-crystal-macro-detail-texture-royalty-free-image/1486708321?phrase=topaz https://www.gettyimages.com/detail/photo/set-of-new-rasp-files-on-gray-background-working-royalty-free-image/1322476771?phrase=steel+file