Ceramic vintage lamp blue jade color pottery porcelain

Hi,
I got this lamp and don't have much info about it. It has a lot of crazing and it looks old. I have both pairs of the lamps. It is in great condition. No breaks or cracks, just crazing.

The wiring has an old Underwriters Laboratories sticker.

I was wondering if they are old pottaries that has been converted into a lamp?
Has anyone seen any lamps like them?
Also how much do you think they are worth?

I do not know much about the lamps, but the person I bought them from told me they are valuable. I would appreciate it if you could please help me.

Thank you very much