Belgium1 Franc 1942- Léopold III BELGIE-BELGIQUE with bumps 4.4 g weight (a little heavy)– 21.5 mm dia. -2.0 mm thickness ( a little thick) My thoughts: Gas bubbles (only one side)? Pattern coin? Morris code? What be your thoughts? Photos with different light shots:
On another post I found this out: Zinc pest, is a destructive, inter crystalline corrosion process of zinc alloys containing lead impurities. It was first discovered to be a problem in 1923. Zinc pest affects primarily die-cast zinc articles that were manufactured during the 1930s, 1940s, and early 1950s. In Germany, articles made from Zamak during World War II and several years thereafter may be affected. Purer alloys were not available to the manufacturers as they were used for the war effort, or were just not on the market after the war. While impurities of the alloy seem to be the cause of the problem, environmental conditions such as high humidity may accelerate the process. Also, significant temperature changes can be damaging. Affected objects may show surface irregularities such as blisters or pitting. They expand, buckle, tear, and in the end, crumble. The irreversible process will eventually destroy the object. Due to the expansion process, attached normal material may be damaged secondarily. Zinc pest is different from a superficial white oxidation process that may affect some zinc articles. Zinc pest is dreaded by collectors of old model trains, toys, or radios where the zinc die-cast process was used. From my research I believe Zinc Pest is the corrosion from within caused by lead impurity and White Rust is corrosion from exterior. Zinc when exposed to the elements will form its own natural self patina layer, and even when scratched will self heal; this process will vary from location to location and can take many years. For zinc to form its own patina it needs to be able to get regularly wet and then dry, if however, it gets wet and the water is allowed to rest on the zinc, White Rust will form. The first sign of White Rust occurring on the surface is a white stain which may increase to a white powder. If this situation persists the White Rust will eventually corrode through the zinc and holes will appear.
