Mohs scale of mineral hardness finding the hardest material that the given material can scratch, or the softest material that can scratch the given material. For example, if some material is scratched by apatite but not by fluorite, its hardness on the Mohs scale would fall between 4 and 5. "Scratching" a material for the purposes of the Mohs scale means creating non-elastic dislocations visible to the naked eye. Frequently, materials that are lower on the Mohs scale can create microscopic, non-elastic dislocations on materials that have a higher Mohs number. While these microscopic dislocations are permanent and sometimes detrimental to the harder material's structural
147 George Street, The Rocks own right. The group is an important part of The Rocks Heritage Conservation Area being sympathetic in scale and character and an extension of the remaining earlier buildings of George Street, presenting a unified streetscape. The buildings are tangible evidence of the redevelopment of The Rocks in the last decade of the 19th century and the first decade of the 20th century, the period before and after the plague outbreak. 147 George Street has high social significance as a contributory element associated with the historic character of The Rocks, which is held in esteem by the local community and to