This is a beautiful diamond halo ring from the mid century.
The diamond is much older than the mounting. The diamond has been bezel set and framed by a hand engraved "x" edge. The diamond is secure and set low for an active woman.

Palladium started to be used in jewelry in 1939 due to WWII's need to use platinum for the military. Palladium is a hypoallergenic alloy that has become a popular white metal alternative in modern jewelry. It is whiter than white gold but not as dense and heavy as platinum.

Gemstones: Diamond
Cut: Early Old European Cut
Weight: 1 = 0.34 cts
Color: I/J
Clarity: VS2/SI1 (natural on pavilion facets)
Measurements: 4.2 x 3.06 mm

Dimensions: 12.6 mm head (4.8 mm high off the finger) / shank 2.5 to 1.4 mm wide
Metal: Palladium
Markings: PALL
Finger Size: 6.5 (inquire about sizing)
Circa: 1940's
Condition Rating: 8 (stone has been checked and mounting has had a light polish)
Weight: 2.5 grams

Thanks for Looking!