1930s German Silver bracelet. Up to well past WWII, Great Britain was the only European country with a Silver standard above 850 ( 850 parts Silver in 1000 parts, 85% Silver content; the UK standard was, still is, and has been for quite a few centuries, 925, i.e. 925 parts in 1000 parts, 92.% Silver content. )
After WWII, the US economy was such that all of Europe wanted to sell there, and the US Silver standard followed the UK 925 standard; by the late 1950s virtually all of Europe had shifted to the 925 standard.
In the 1930s in Europe the Silver standard varied country to country, and even within countries; though France seemed to have a uniform 800 Silver standard, in Scandanavia and in Germany it could vary from 830 through to 850.
In any case, it is important to note that any item of 80% + Silver purity should be considered genuinely Silver, certainly not base. In India, by far and since Antiquity the greatest Silver jewellery region on earth, anything 80% and up is proper Silver. The Indians used never, and still often do not, stamp Silver, for any dealer in that region can ascertain the quality of Silver in an item, within 2%, by the sharpness of the sheen left on rubbing the item against a type of black granite rock.

Amazonite, the gemstones set in the above 1930s German Silver bracelet, has been used in jewellery since ancient times. It gained a resurgence in jewellery use in the early 1900s, especially in northern Europe, when all sorts of relatively obscure gemstones, cut cabochon, were used in Silver jewellery.