Jack Weekoty (also spelled Weekooty) was a Zuni artist born in 1916.
He produced jewelry from 1945-1975.
His hallmark, as shown in the photo below, is JW with a design around it that looks like a little shed with a roof and walls however some have interpreted the design as clouds and rain.
This is important because a more contemporary Navajo artist, Juliana Williams, also uses the JW hallmark but without the design around the initials.
Paula