chemical weathering of granite rocks

algae asia batok big biological biotite boulder brown bukit change chemical clay coarse color colour crack discolouration discoloured edge erosion exfoliation fault feldspar fine fragment geomorphology grains grainy granite grass gray green greenery grey hard humid hydration igneous ion iron large layer leaves line material matter mechanical metal mineral minerals moist natural nature outcrop oxidation oxide oxidised physical plane plants process quartz resistant rocks rust sediment singapore solid spherodical stone surface texture tropical vegetation water weakness weathered weathering