My favorite lamp growing up

I am hoping someone can help me identify exactly what type of lamp this is. The only history I have on it is that it was buried in the basement of my childhood home. My parents bought the house probably around 1954. It was an old 1890 farmhouse. The basement ceiling was very low and had a dirt floor. Being over 6 feet tall my dad dug the basement floor down to give more ceiling height. This lamp was buried in the floor of the basement. The original metal band and hanging bracket were rusted out and my dad had them redone. All else is original to the lamp. It is real glass and real lead. It is approx. 2 feet across. It's big! My mother was told it is a Tiffany. Does anyone know if this could be true? If not any ideas what type it is? Thanks in advance for any help you can give!