Thank you for submitting your item for appraisal. This appears to be a 1960s or 1970s slag glass leaded lamp shade / pendant lamp manufactured in the tradtion of Tiffany. Such lamps were made in huge numbers when demand was high. The taste has shifted today and supply of similar is high. The estimate is based on similar sold at auction. There is no measurement for the sentimental value you might attach to the item.