If the marble headstone is in good condition proceed to the next step.
Marble tombstone weathering.
Marble for example is assumed to decay mainly through dissolution by acidic rainfall natural rainfall is slightly acidic being a weak carbonic acid with a ph of 5 6.
Physical weathering is the toll put on rocks by processes like frost ice splitting abrasion from things hitting it plant roots decompression at the surface remember most rocks are formed.
Thaw weathering as temperatures fall faster in the open air than under trees.
Weathering rates of marble in urban environments eastern australia.
First check the condition of the marble headstone that you want to clean.
Dragovitch 1986 an excellent source of data for tombstone weathering in two different cities.
Marble tombstone weathering and air pollution in north america thomas c.
Meierding department of geography and center for climatic research university of delaware newark de 19716 fax 302 831 8273 e mail buc18279 um udel edu abstract.
Maps of surface recession rates measured from 8 438 century old vermont marble tombstones at 320 cemeteries.
Since marble is vulnerable to wear and tear marble headstones that have cracks and signs of aging should be left as is because cleaning can weaken the marble further and result in more serious damage.
Therefore in west yorkshire the back of the headstone faces the prevailing winds so should be more weathered.
Aspect is the compass direction in which the headstones face.
Gravestone weathering department of geography.
This removes matrix and grains from the surface of the gravestone leaving a rough sugary feel.