Absolute minimal maintenance is required for a polished granite memorial:
Polished Granite - Polished surfaces easily wash with water and a sponge. Abrasive cleaners and materials can scratch the polished surface and should never be used. Never use wire brushes or steel pads, only use soft bristle, non-scratch brushes and sponges.
Granite memorials should be carefully swept or dusted before applying any pressure to the surface to prevent dirt and grit causing abrasive action on the polished surface.
Oil and grease should be soaked up quickly and not wiped from surface as it will spread and penetrate the surface, leaving a stain. The residual stain can be partially dissipated into the granite by absorbing with a non-oily solvent, i.e. Toluene, white spirits, methylated spirits.
Melted candle wax can soak in and stain granite. When the granite is heated by the sun, candle wax melts, penetrating the surface, resulting in stains that cannot be fully removed.
Unpolished Granite - Unpolished surfaces may need high pressure water blasting once every few years or so, depending on climate & positioning of the memorial.
Gold Letters - Squeeze a clean wet sponge above lettering to allow water to gently flow down over the gold. Never touch the gold with hands or fingers - oils from the skin will react with the gold and cause it to discolour. Never wipe gold, as every contact removes a minute layer of the gold leaf. Gold can be re-gilded when required, but only by a skilled tradesperson.