Hi - providing it's a TRIANGLE and not a Diamond SHAPE, the mark could be that of J.J. White Mfg Co. [later SAMSAN Co.] Manufacturing Jewelers, Providence, RI, USA - ca 1888 - 1973
The mark looks, from one angle like a small circle at the very tip of the triangle point where the two lines meet. There is no space between the triangle and the circle.
