These are unofficial game parts. They are a millimeter or two shy of the exact size of the game rubies including height (see photo for size comparison) - they're very close but not exact but I'm selling five of them so you can replace all of your rubies with these ones if you wanted to (please be aware, older Buccaneer games have six rubies not five).

They are most suited to the 1975 red box version but you can probably use them for most versions if you wanted to.