GRANITE , SLATES , QUARTZITE , SANDSTONE , QUARTZ , SOAPSTONE
GRANITE , SLATES , QUARTZITE , SANDSTONE , QUARTZ , SOAPSTONE
NATURAL SLATE IS A DENSE FINE-GRAINED METAMORPHIC ROCK PRODUCED BY THE COMPRESSION OF VARIOUS SEDIMENTS (AS CLAY OR SHALE) THAT CAN BE EASILY DIVED INTO THIN PIECES. IT IS FREQUENTLY GREY IN COLOUR ESPECIALLY WHEN SEEN IN ROOFS. HOWEVER, SLATE OCCURS IN A VARIETY OF COLORS EVEN FROM A SINGLE LOCALITY.
BRAZILIAN SLATES ARE INCREDIBLY DURABLE AND CAN LAST SEVERAL HUNDRED YEARS, OFTEN WITH LITTLE OR NO MAINTENANCE. ITS LOW WATER ABSORPTION MAKES IT VERY RESISTANT TO FROST DAMAGE AND BREAKAGE DUE TO FREEZING.