Native American Antique/Vintage Rare Bisbee Turquoise Brooch Pin Arrow Maker’s M

Deep Blue almost Ocean blue with spots of light blue and dark brown web. In bright light I can see lighter blue colors here and there but in natural light it looks deep blue. There’s an arrow maker’s mark in the back, Sterling silver, huge Turquoises, I cannot take stone out of brooch to weigh it, it is a little more than an inch long and half an inch wide. It looks like Antique, define Native American my guess is Navajo. Did test real turquoise. Antique, should probably be in a museum.