It is possible to have the stone on your 2-carat marquise diamond ring lose its luster because you did not take adequate care of it. Following are some of the factors, which could lead to something like that.   Exposure to Soap and Water It is never smart to step into the shower wearing jewelry because soap and water does it no favors. Take off your rings first, and forget the easy-cleaning idea your neighbor suggested you try out. The soapy solution that experts use for cleaning diamonds is actually shampoo and water, with no soap in it. Touching Sweat and Dirt We secrete oil from skin pores, which mixes with sweat to form a goo that when combined with dust, gives something that could do no one any good. Diamonds getting dabbed with this a lot, would have a much higher chance of looking altogether shabby even under the best lighting. Contact with Deodorants and Perfumes The thing about deodorants and perfumes is that they contain corrosive chemicals, which while relatively harmless for your skin, are bad for gems that are supposed to shine.