Hi Teri,

Thank you for contacting Mearto with your appraisal inquiry.
This lamp looks like a later reproduction after originals made by Tiffany in the early 20th Century and I'd be surprised if this lamp (shade, base or both) were stamped TIFFANY & CO or LCT or TIFFANY STUDIOS. However, if it marked that way, please let me know as it would be more valuable.
Based on the photos and information provided, and subject to examination, this is:

An Art Nouveau style slag glass and bronze table lamp
American, first half 20th Century
surmounted by a domed shade with 8 sections with yellow glass above and blue banding below, on a bronze lamp with lobed base. Apparently unmarked.
overall height 24 inches, diameter of shade 31 inches
PROVENANCE: inherited
$150-250*
*represents a fair-market value for auction purposes; retail or asking price may vary.

Please let us know if you have additional items to appraise, and thank you again for using Mearto.