LOST MY PAN FOR MINING FROM LAKES AND STREAMS!

Help! I just noticed that the mining pan Willy gave me when I cleared the gemstone boulders next to the Mine has vanished from my inventory! My entire farm is extremely organized - so even though I do have many, many chests, each chest holds very specific items and they are all placed in very specific locations. I have checked every chest I have and it is not in any chest. It cannot be sold and I have tried to see if Willy can give me another one or if I can even buy one somewhere. But I can't seem to find any way to replace it. Has anyone else lost their mining pan and if so, did you find a way to get it back? There's nothing about it on the Wiki page. Thanks!