One of the scariest things Archaeology and Collections Branch (ACB) Senior Archaeologist Aimee Wells has encountered is well-meaning people using methods to clean gravestones  that are harmful to the stones’ longevity.  Even so-called “gentle” cleaners can be damaging to gravestones depending on their material, age, and condition. Many cleaners on the market rely on chemical solvents that can   wear down an object’s surface. This is particularly damaging to  gravestones as they are meant to be an enduring marker and excessive cleaning can erase inscriptions and decorations. 

Despite the threat of over-cleaning, under-cleaning can also threaten our cemeteries. Dirt, pollution, and biological organisms like mold, algae, and moss can cause damage or staining to headstones—eroding details and destabilizing stone. Wells and the County Archaeological Research Team (CART) must balance these opposing threats to headstones. 

Prior to cleaning any  gravestone, CART evaluates the stability of the stone and the suitability of their cleaning method. The stone pictured below was covered in biological growth, but this was easily cleaned by trained staff using a soft bristled brush and distilled water (video here). After cleaning, the decoration and inscription are easier to read, and the stone isn’t damaged for future generations.

CART is helping owners of cemeteries learn how to care for them. A cemetery preservation manual is available at Cemetery Survey website.