A positive vigorous reaction indi.
Muriatic acid on granite.
The instructions on the cans for cleaning brick first of all.
If the acid is left on long enough the stone can degrade further and cause an indentation.
Hcl will kill off the lice and lichens.
Limestone marble and granite are just a few of the natural stones available.
Wear safety goggles and a nose mask.
You will notice some fizzing of the acid which is fine.
Also avoid acids such as muriatic acid or phosphoric acid as they can damage the surface.
Since muriatic acid can damage or kill foliage cover or wet all nearby foliage with water before application of the acid.
Do not use normal household cleaners soaps and detergents ivory formula 409 bleach tsp laundry detergents dish detergents etc to clean headstones.
Muriatic acid not diluted 100 percent strength was used to clean the grout on floor tile in an existing bathroom and now the metal items in the room look pitted and tarnished.
The acid test is one of dropping cold dilute 10 hydrochloric acid hcl on a mineral or rock.
If the foliage has been accidentally sprayed with acid a neutralizing mix of lime and water can be applied to the plant and or soil.
If the acidic product sits on the surface for too long or if your granite is very porous it can even result in indentations or erosion.
This damage of the surface often shows as dull etch spots on the surface but it can also affect the entire surface of the granite if you use acidic cleaners.
Whether your tombstone is young or not is immaterial.
Link to product info on amazon lying around may i suggest you pop into your friendly lumber yard store and ask to see.
Granite is much more resistant to acid etching because it contains little to no calcite though the stone still has natural pits and fissures that can trap acids and degrade slowly over time.
Let the baking soda garden lime sit on the acid solution until the solution is absorbed into the baking soda garden lime time will vary.
Muriatic acid is a heavy duty chemical that will clean away dirt soap scum and efflorescence from your natural stone and masonry items.
Used for tiles walls and countertops grime will quickly cover your stone item and require a thorough cleaning.
Pressure washers can be used to clean granite headstones but use caution around the carved areas.