<Table> <Tr> <Th> Hardness </Th> <Th> Substance or mineral </Th> </Tr> <Tr> <Td> 0.2 -- 0.3 </Td> <Td> caesium , rubidium </Td> </Tr> <Tr> <Td> 0.5 -- 0.6 </Td> <Td> lithium , sodium , potassium </Td> </Tr> <Tr> <Td> </Td> <Td> talc </Td> </Tr> <Tr> <Td> 1.5 </Td> <Td> gallium , strontium , indium , tin , barium , thallium , lead , graphite , ice </Td> </Tr> <Tr> <Td> </Td> <Td> hexagonal boron nitride , calcium , selenium , cadmium , sulfur , tellurium , bismuth , gypsum </Td> </Tr> <Tr> <Td> 2 -- 2.5 </Td> <Td> halite ( rock salt ) </Td> </Tr> <Tr> <Td> 2.5 -- 3 </Td> <Td> gold , silver , aluminium , zinc , lanthanum , cerium , Jet ( lignite ) </Td> </Tr> <Tr> <Td> </Td> <Td> calcite , copper , arsenic , antimony , thorium , dentin </Td> </Tr> <Tr> <Td> 3.5 </Td> <Td> platinum </Td> </Tr> <Tr> <Td> </Td> <Td> fluorite , iron , nickel </Td> </Tr> <Tr> <Td> 4 -- 4.5 </Td> <Td> steel </Td> </Tr> <Tr> <Td> 5 </Td> <Td> apatite ( tooth enamel ) , zirconium , palladium , obsidian ( volcanic glass ) </Td> </Tr> <Tr> <Td> 5.5 </Td> <Td> beryllium , molybdenum , hafnium , glass , cobalt </Td> </Tr> <Tr> <Td> 6 </Td> <Td> orthoclase , titanium , manganese , germanium , niobium , rhodium , uranium </Td> </Tr> <Tr> <Td> 6 -- 7 </Td> <Td> fused quartz , iron pyrite , silicon , ruthenium , iridium , tantalum , opal , peridot , tanzanite , jade </Td> </Tr> <Tr> <Td> 7 </Td> <Td> osmium , quartz , rhenium , vanadium </Td> </Tr> <Tr> <Td> 7.5 -- 8 </Td> <Td> emerald , hardened steel , tungsten , spinel </Td> </Tr> <Tr> <Td> 8 </Td> <Td> topaz , cubic zirconia </Td> </Tr> <Tr> <Td> 8.5 </Td> <Td> chrysoberyl , chromium , silicon nitride , tantalum carbide </Td> </Tr> <Tr> <Td> 9 </Td> <Td> corundum , tungsten carbide , titanium nitride </Td> </Tr> <Tr> <Td> 9 -- 9.5 </Td> <Td> silicon carbide ( carborundum ) , titanium carbide </Td> </Tr> <Tr> <Td> 9.5 -- 10 </Td> <Td> boron , boron nitride , rhenium diboride ( a-axis ) , stishovite , titanium diboride </Td> </Tr> <Tr> <Td> 10 </Td> <Td> diamond , carbonado </Td> </Tr> <Tr> <Td> > 11 </Td> <Td> nanocrystalline diamond ( hyperdiamond , ultrahard fullerite ) , rhenium diboride ( c - axis ) </Td> </Tr> </Table>
<Table> <Tr> <Th> Hardness </Th> <Th> Substance or mineral </Th> </Tr> <Tr> <Td> 0.2 -- 0.3 </Td> <Td> caesium , rubidium </Td> </Tr> <Tr> <Td> 0.5 -- 0.6 </Td> <Td> lithium , sodium , potassium </Td> </Tr> <Tr> <Td> </Td> <Td> talc </Td> </Tr> <Tr> <Td> 1.5 </Td> <Td> gallium , strontium , indium , tin , barium , thallium , lead , graphite , ice </Td> </Tr> <Tr> <Td> </Td> <Td> hexagonal boron nitride , calcium , selenium , cadmium , sulfur , tellurium , bismuth , gypsum </Td> </Tr> <Tr> <Td> 2 -- 2.5 </Td> <Td> halite ( rock salt ) </Td> </Tr> <Tr> <Td> 2.5 -- 3 </Td> <Td> gold , silver , aluminium , zinc , lanthanum , cerium , Jet ( lignite ) </Td> </Tr> <Tr> <Td> </Td> <Td> calcite , copper , arsenic , antimony , thorium , dentin </Td> </Tr> <Tr> <Td> 3.5 </Td> <Td> platinum </Td> </Tr> <Tr> <Td> </Td> <Td> fluorite , iron , nickel </Td> </Tr> <Tr> <Td> 4 -- 4.5 </Td> <Td> steel </Td> </Tr> <Tr> <Td> 5 </Td> <Td> apatite ( tooth enamel ) , zirconium , palladium , obsidian ( volcanic glass ) </Td> </Tr> <Tr> <Td> 5.5 </Td> <Td> beryllium , molybdenum , hafnium , glass , cobalt </Td> </Tr> <Tr> <Td> 6 </Td> <Td> orthoclase , titanium , manganese , germanium , niobium , rhodium , uranium </Td> </Tr> <Tr> <Td> 6 -- 7 </Td> <Td> fused quartz , iron pyrite , silicon , ruthenium , iridium , tantalum , opal , peridot , tanzanite , jade </Td> </Tr> <Tr> <Td> 7 </Td> <Td> osmium , quartz , rhenium , vanadium </Td> </Tr> <Tr> <Td> 7.5 -- 8 </Td> <Td> emerald , hardened steel , tungsten , spinel </Td> </Tr> <Tr> <Td> 8 </Td> <Td> topaz , cubic zirconia </Td> </Tr> <Tr> <Td> 8.5 </Td> <Td> chrysoberyl , chromium , silicon nitride , tantalum carbide </Td> </Tr> <Tr> <Td> 9 </Td> <Td> corundum , tungsten carbide , titanium nitride </Td> </Tr> <Tr> <Td> 9 -- 9.5 </Td> <Td> silicon carbide ( carborundum ) , titanium carbide </Td> </Tr> <Tr> <Td> 9.5 -- 10 </Td> <Td> boron , boron nitride , rhenium diboride ( a-axis ) , stishovite , titanium diboride </Td> </Tr> <Tr> <Td> 10 </Td> <Td> diamond , carbonado </Td> </Tr> <Tr> <Td> > 11 </Td> <Td> nanocrystalline diamond ( hyperdiamond , ultrahard fullerite ) , rhenium diboride ( c - axis ) </Td> </Tr> </Table>
how hard is graphite on the mohs scale
how hard is graphite on the mohs scale
1.5
1.5