These coins were minted in the historical region of West Friesland, located in the Netherlands. It existed as a separate state with the authority to mint its own coinage until it became a part of North Holland in 1800.
The coins are made of silver, but with a purity of just under 60% and a weight of less than a gram per coin, (0.81 grams for genuine coins) they can hardly be considered for their bullion value.
A nice amount of these coins were made, with several hundred thousand minted in the better years, which helps keep collector values low for worn coins with tainted eye appeal. However, one like David's, with its average wear and likable eye-appeal, will be worth a nice chunk of money.
Here are some approximate catalog values for these coins:
worn: $2 US dollars
average circulated: $20
well preserved: $40
fully uncirculated: $100
There is one more aspect about David's coin to discuss - its toning. Some collectors prefer coins with a natural look, but many collectors, such as myself, will pay premiums for coins with exceptional toning. An average circulated coin with likable eye appeal and colorful toning may sell for $30 or so to the right collector.
Damaged coins will be worth much less than the values quoted above. Refer to our 'Important Terminology' page on the top left in order to properly interpret the catalog values mentioned on this page.