Archaeologists Clean Dirty Monuments With Face Packs

Makarand writes "According to this article on indiaExpress.com archaeologists at the world famous Taj Mahal (Agra, India) are using a face-pack consisting of soil, cereal, milk and lime to beautify the monument. This recipe called 'Multani Mitti', which translates as 'mud from Multan,' is based on a beauty formula from the 16th century and contains lime-rich clay found in Multan (now a part of Pakistan) which was used for thousands of years as a face-pack by Indian women. The sticky brown mixture is smeared on the pollution-stained marble surfaces of the monument and washed off with warm water after 24 hours. Scientists from Italy have shown interest in these face-packs to restore their marble statues. The BBC News article says the same thing but has pictures."

Comments

Re:Good!

[DarthWing]

Ok, I'll bite...

The mud draws out the polluting sulphates and carbonates.

I'd imagine that the active ingredient would be the lime (CaO), which reacts with the pollutants in the following manner:

CaO + XCO3 -> CaCO3 + XO

.

Notice that one of the products, CaCO3, is the chemical formula for marble. In a similar manner, the lime reacts with sulfates to produce CaSO4, which would most likely take the form of gypsum, which I'd imagine would contribute to the bright white finish.

In a bieore commercial

[seann]

it features this art restoration expert, using some kind of bieore type strip (professional brand type most likley) to remove dirt and grease from art on a wall.
Rather interesting use I thought...Now I know it's actually real.
People do that.