Signed Dale Tiffany Mosaic glass lamp

.. It has  beautiful pink, blue  and green color glass or mosaic glass in it. The design is in the shape of flowers that are several tones of  pink, with several tones of  green for the leaves and has a clear glass for the center of the flower. The rest is in different shades of blue.  It is a beautiful lamp. It has the original cord and sits on a metal base, and the cord has the on off switch on the cord. On the inside rim of the glass at the top is a  band that has the signature Dale Tiffany, etc, unable to make out the last word. It is in excellent condition  with no chips or breaks in the glass not sure exactly what the glass is, is it stained glass or mosaic and is it worth anything?