Show the hardest metal the hardest metal is titanium this metal was first recognized by mr gregor 9 or in 1791 but its properties were not satisfactorily determined until 1822 when dr wol on jn examined it and described it as it occurred in its perfect metallic and crystallized state in the slag of an iron furnace at merthyr tydfil in south wales the form of the crystals is the cube their color resembles that of bright copper they are sufficiently hard to scratch rock crystal and their specific gravity is 53 according to M dumas the order of metals with reference to hardness is as follows chromium rhodium which cannot be scratched with glass nickel cobalt iron antimony zinc scratched by glass palladium platinum copper gold silver tellurium bismuth cadmium tin scratched by carbonate of lime lead scratched by the nall nail and potassium and sodium which are as soft as wax |