Undated
Abel Bros. & Co.
Source date listing: c.1896, c.1904, c.1915, c.1922, c.1934, c.1950, c.1943.
New York NY, United States
Cartouche, octagon, rectangle, square
Read the stamp
What does PT900 mean on jewelry
950PT and PT950 both describe 950 parts platinum per thousand; PT900 describes 900 parts. A bare 950 can also occur on silver.
Platinum fineness numbers
PT is the metal abbreviation. 950PT and PT950 both describe 950 parts platinum per thousand; PT900 describes 900 parts. PLAT and PLATINUM are word forms.
What to check next
A bare 950 can also occur on silver. Read the metal name and hallmark surround before assigning it to platinum. White colour alone does not separate platinum, palladium, white gold and silver. Check any independent maker or sponsor punch beside the metal designation.
Related marks
17 marksG.C. & G. Manufacturing Co.Maker name
NYMark wording
Undated
Gold Bros. Inc.
gold · New York NY, USA
c.1950: 7 W. 45th St. New York 19, | c.1943: 7-11 W. 45th St. New York 19, | From their JCK Advertisement: | Gold and Platinum Novelties
NYMark wording
Undated
Katz & Ogush Inc.
New York NY, USA
e. 1926 as Ogush Brothers (William B. & Benjamin) | c.1930: Benjamin S. Katz joined the firm and it became Katz & Ogush | c.1934 – c.1950: 33 W. 60th St. New York | Specialties: Platinum single stone rings, wedding rings, dinner rings, flexible bracelets, pendants, brooches, sautoirs, scarf pins, chains, bar brooches, clasps for necklaces | c.1936: Ogush gained control of the company. | c.1941: Death of Benjamin Ogush, Business Name Wm. B. Ogush Inc. | c.1951: Katz was president of the Gruen Watch Company and acquired control of the Ogush business. | c.1952: Ogush founded the Diamond Watch Company, 608 Fifth Avenue . | c.1956: Death of William B. Ogush.
Undated
The Miller Jewelry Co.
The source entry lists c.1915, c.1934, c.1943.
Cincinnati OH, United States
M, m 12k top, m 10k, m 18k, m platinum
Undated
France gold and platinum
gold, platinum · France
French assay or guarantee marks described as an eagle head and a dog head.
French platinum guaranteeMaker name
CANMark wording