So first we cleaned it with hot water and some soap, and after that my granddad polished it for 5 minutes, and the result was really nice. The spoon has the text Ole Luk Øje standing on the shaft. It refers to one of H. A. Anderson's stories which you are able to read more about here.
I looked up the spoon on Google, and found it from brand new. It costs 172 US $ or 143 euros. The spoon is 3 tower silver (a danish mark), which means that its at least 82.6 % pure silver.
But silver isn't magnetic, so how come you caught it, you may ask?
As you can see in the first two pics above, there is kind a clear difference between the part you put in the mouth and the shaft, the shaft is all black, that is because it is the silver. The end you put in your mouth is made of stainless steel for some reason, so this was the part which stuck to the magnet.
My grandmother said that this is because some people don't like to put silver in their mouth, so they make it stainless steel.
I know it's not new looking, but this is the end result.