White Gold was invented in 19th centruy. In America, Bliss Brothers started promotion of White Gold at late Edwardian era(1900-1910). White Gold was very hard to work with and required many times of annealing in fabrication process. However, 18 Karat gold, meaning; %75 gold and %25 alloy, was easier to work with than 14 Karat(%58.3 gold and %41.7 alloy).
The main challenge was to keep the color white(steel color/Platinum color) after many months of usage because gold is yellow in nature. Today, we typically use Copper, Iron, Nickel, Tin and Aluminum as alloys in jewelry and at the end of the process almost all White Gold production gets Rhodium plated. But the challenge of Art Deco jewelers was to produce a product which doesn't need plating. Plating was considered faking the look. So, the alloy was the best kept secret of designers.
Today, one could X-Ray the metal and find out the exact alloy material in Art Deco jewelry.
Your 'Orange Blossom' band is missing some diamonds. Those should be replaced by Single Cut diamonds for correct restoration. Do not ever hard polish the band. More in-depth details, higher the value.
Cute band,
