When tested with X-ray, these stones are opaque.
Due to the potential of to cause damage to the , may be used only a limited number of times over a patient's lifetime.
Stones that are opaque to short wave ultraviolet are seen as white spots, whereas the centers are exposed and appear as dark spots on those that are transparent to short wave ultraviolet.
Five sunscreen ingredients have been shown to protect mice against skin tumors.
Colors change within seconds, take a little longer to fade back to white.
This phenomenon is noted most often when invisible ultraviolet light is directed at a gem material and when the new wavelength given off is in the visible spectrum.
I created a 5 station activity where students rolled a die to see what happened to their oxygen molecule.