The most common dangers to turquoise are of two types: The first is direct damage caused by scratches or sharp blows. This is due to its relative softness as a gemstone, but any gem can be damaged by sharp, hard impacts. With a little caution, it is easy to prevent this type of damage - avoid heavy work when wearing your turquoise. The second problem is color changes, which can caused by oils, soaps, lotions or other household chemicals. Because all natural turquoise is at least a little porous, things like oils, soaps and other chemicals can get into the stone and can change its color. The pores of the stone will even absorb the natural oils produced by the skin causing it to turn a greenish color over time. In even the hardest turquoise, deposits collecting in the pores of the stone can eventually cause a color change. Therefore, just a little care should be taken to protect the stones from situations where they may be exposed to oils, grease and chemicals - again, its best to avoid heavy work when wearing your turquoise. Once a stone changes color, unfortunately it's changed for good.