Look at this gorgeous coin in the picture. It comes from TreasureRealm in Wyoming, USA. CoinQuest thanks TreasureRealm for use of their coin photo. It is a beauty!
William (Gulielmus) and Mary ruled Great Britain from 1688 to 1694. This half crown shows their images on the front (obverse) and the coats of arms of England and France on the back (reverse). There are other half crowns with William and Mary and a different reverse that the one shown here. For that coin, click to this CoinQuest page.
The catalogs give very approximate values for coins without problems such as scratches, stains, spots, corrosions, cleanings, and the like as follows:
HALF CROWNS DATED 1689
worn: $70 US dollars approximate catalog value
average circulated: $500
well preserved (like the picture): $2500
The 1690 date is more rare than the 1689 date. Double the values above for coins dated 1690.
As always on CoinQuest, these are very approximate values that must be adjusted using the concepts on our Terminology page. TreasureRealm's coin is in such wonderful condition, without much wear and with gorgeous eye appeal, it comes in at the high end of our value scale.