The absurdly named "Appearance of Pirate's Fossil" was a Chinese-made toy that was frequently found in US dollar stores several years back, consisting of a card stock "treasure chest" containing a block of dried, hardened sand and three tiny plastic tools - a hammer, a shovel, and a paintbrush.
You were supposed to use the hammer and shovel to smash and break apart the sand block to find a cheap plastic trinket such as a plastic ring or a plastic coin. You would then use the brush to brush of any remaining sand particles to reveal your "treasure" in all its plastic glory.
The packaging was also somewhat memorable, with both the display box and each individual "chest" featuring a large image of a skull with an eyepatch and a tricorn, repeatedly urging you to "Dig! Dig! Dig! Dig! Dig!"
Obligatory image can be found here: http://www.barryowen.com/productProfile.php?prodID=3870