Why once-gold ceilings in Spain’s Alhambra palace have purple stains
Why once-gold ceilings in Spain’s Alhambra palace have purple stains,Moisture infiltrated flawed gilding at the iconic palace, leading to corrosion that deposited gold nanoparticles of the right size to appear purple.

Why once-gold ceilings in Spain’s Alhambra palace have purple stains

Moisture infiltrated flawed gilding at the iconic palace, leading to corrosion that deposited gold nanoparticles of the right size to appear purple.