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