This monogram was created by AA Turbayne, in the book Monograms & Ciphers, London, England, (1906). 

Monogram: MOM

Accents/Accessories: Loose bail; Torn edging; Smooth finish; Lightly oxidized

Size: 39 x 29 millimeters (1.54 x 1.14 inches)

Weight: 8.50 grams (0.30 ounces)

Sterling Silver Chain as shown: 16 inches - $25.00 or 18 inches - $35.00