Copper(II) carbonate
Copper(II) carbonate (often called copper carbonate or cupric carbonate) is a blue-green
compound (chemical formula CuCO3) forming most of the
patina one sees on weathered
brass,
bronze, and
copper. The colour can vary from bright blue to green, because there may be a mixture of both copper carbonate and basic copper carbonate in various stages of
hydration. It was formerly much used as a
pigment, and is still in use for artist's colours. It has also been used in some types of make-up, like
lipstick, although it can also be poisonous to humans. It also has been used for many years as an effective algaecide in farm ponds and in aquaculture operations.
See more at Wikipedia.org...
Vert-de-gris
Infrarød stråling
Ir
Ir opstår, når
grundstoffet kobber tilføres en blanding af svovldioxid, kuldioxid og vand. Restprodukterne er også kendt som kobbersulfat CuSO4, kobbercarbonat CuCO3 og kobberhydroxid Cu(OH)2. Kobbertage der udsættes for vind og vejr, får et tyndt lag ir. Det består af mineralet malakit — Cu2CO3(OH)2.Ir ses især på gamle tårne på slotte og kirker i København, der traditionelt i Danmark er beklædt med kobber. Der går typisk et sted mellem 3 og 15 år før kobberet begynder at blive grønt pga. ir.
Se mere på Wikipedia.org...