Read the stamp
PLAT stamp on ring
In a PLAT stamp on ring, PLAT and PLATINUM are word forms. White colour alone does not separate platinum, palladium, white gold and 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
37 marks
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
Undated
Dinhofer Bros. Inc.
Recorded around 1922, 1950; a continuous mark-use interval is not specified.
New York NY, United States
Undated
Eiseman, I. & Son.
Recorded around 1915, 1922, 1934; a continuous mark-use interval is not specified.
Pittsburgh PA, United States
G.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
Undated
J. Milhening Inc.
The source entry lists c.1915, c.1934, c.1950, c.1943.
Chicago IL, United States
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
Martin Flyer Inc.
The source gives establishment notation e.1944; separate mark-use dates are not specified.
New York NY, United States
Undated
The Allsopp-Bliss Co.
Source date listing: c.1922, c.1934.
Newark NJ, United States
Cartouche, , frame, medallion
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
Explore makers & marks
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