smoking
dirt
The deep *vertical* lines in your fingernails are genetic. If you have *horizontal* ridges in your nails, you should see a doctor.
picking warts on your bum and casual worms.
Fingernails are normal in the human body. Please be more specific in your question.
Keratin... it's a natural substance that makes the nail harden.
Yes. Darkening is most commonly used as a verb, but it can be an adjective. In a sentence like "Under the darkening clouds" it is an adjective.
Darkening Sky was created on 2010-10-22.
Mona on Darkening Ground was created in 2001.
Fugue for a Darkening Island was created in 1972.
cheese is great and other people like it 2.
The white area in fingernails and hair are caused by air. That's why snow is white and not blue. Little bumps and bruises that are done to the bed of the nail cause these imperfections.