When there is uncertainty in a nations economy, government or currency, people will use their fiat money to buy precious metals, historically this has been gold or silver and the increased demand in the precious metal causes its value to increase. In some countries, like Switzerland and Liechtenstein, bullion bars can be bought or sold over the counter at major banks but one need not go far to buy gold or silver, it is commonly found in coins but not all coins have precious metals in them. It takes some knowledge to hoard the silver floating around.
The large size and weight, an open design and a clumsy manufacturing process combined to make the Australian crown notorious for bag marks, dings and rim nicks. After striking, the coins were transported by a conveyor belt and dropped into a collection bucket. There are numerous examples of coins which display a neat row of tooth marks imparted by the reeded edge of another crown.
Finding a 1937 or 1938 without any marks at all is very, very rare if presented with an example within your means, it would be a great addition to any collection. Discussions with another collector have also revealed a very interesting point about the 1938 issue. Having handled the 1938 Crown proof, he noticed the cross on the orb, a strong grading reference point, was not present on proof strikes, to him this indicates that most 1938 crowns could have been under graded.
As with all denominations of Australian coins did not go 50% silver until 1946, note the Australian Florin (1910-1945)
From 1947 until the introduction of decimal coinage in 1971, British pre-decimal coins issued for circulation were made of copper-nickel or other metals, and contained no silver
Note: the U.S.A market being large is the focus of much of the counterfeiting and many Morgan Silver Dollars I believe out there are counterfeit. The ways of testing if the coin is real, is firstly by using a very powerful Neodymium magnet, the authentic coin should be non-magnetic, secondly by its frequency compared to a real silver coin of the same weight. Balance the coin on the tip of your finger, tap the coin with another coin note the resonance of silver. Thirdly the weight of the coin should be exact or ever so slightly less accounting for wear.
After 1964 the Federal Government stopped minting silver coinage, save for an attempt at continuation within the 40% Silver Kennedy Half-Dollar until 1970. The circulation edition of the Eisenhower Dollar was copper-nickel clad.
Other coins… 10 Lira from 1926 to 1930 has 83.5% silver for 0.2684 oz, the 5 Lira from 1926 to 1930 and the 2 Lira from 1861 to 1917 both have identical 83.5% silver for 0.1342 oz
No German silver coins were struck after 1939, only these contain silver. AFAIK you will not find big silver German coins and prior to 1870 you are seeking Prussian or Saxony coins called “pfennig” and further back into non-unified coinage all of which are too rare to mention here, the Nazi era coins are by far the most plentiful.
Other coins… 3 Marks from 1924 to 1925 and the 3 Reichsmark from 1925 to 1933 both have 50% silver for 0.2411 oz and the 5 Marks from 1951 to 1974 has Silver 62.5% silver for 0.2250 oz.
It may become an issue with some coins being too dirty and too worn that one viewing their albums seeks to upgrade a coin, so their is coin grading and is a way to suggest the condition of a coin.
Exceptions are errors and damage caused at the mint. Other than condition grading, their may be mint markings that suggest where a coin was minted that can effect its standing and a coins rarity. Coins are generally affordable, a penny is still worth a penny a hundred years later so its always fun to include the differences.
A collection of coins well kept in a ring folder with acid free coin holders and pages will tend to be thicker at the top than it is at the bottom, due to a set equaling less than twenty, a typical amount of inserts in an album page and why don't we use that space for fillers. Fillers are coins that are not immediately part of a set but are included because they are interesting as their is a place for them to be included. It is my personal opinion that cupronickel should never be rewarded so fillers do not include commemorative coins which should be avoided and rejected in all cases unless the commemoration is adequately important that the coin is made of a valuable element as special for the commemoration. It is my personal opinion that very old coins belong in museums and not part of collections. Fillers are generally cheap coins, affordable so one can embellish bidding comfortably while staying well within limits, ultimately their are no rules or you make your own rules so take some time to find some interesting fillers and spice up your collections.