I have noticed that the large moss rock fireplace and walls are changing as the winter turns into spring. The moss rock walls have more colors (black blotches, colors, more textures, etc.), BUT, I have seen the same/similar patterns on the rug ... Is this unusual? Will the blooms stop? Is this a health hazard? Have you heard of this before? What should I do?! Thank you Bob Villa - nice hot rod race with Tooltime Tim Taylor!!