Finding a tin or aluminum gift for your significant other for a traditional 10th anniversary present can be a bit tricky. You want to choose something which symbolizes your feelings, but most items made from the material aren't romantic or very valuable. For this reason, a tin present might make a better supplementary gift.
Tin boxes provide a versatile option. You can find ones already filled with goodies, such as RedEnvelope's cookie tins, or you can fill them on your own. Consider including jewelry, photographs of the two of you together, bath and beauty products and anything else which you think your significant other might enjoy. Here's your chance for creativity. Try to find a tin box large enough to hold all the gifts you wish to include, but not so big as to dwarf them and make the box look empty.
While tin doesn't typically come to mind when shopping for jewelry, it is still possible to find pieces made from aluminum or similar the less-precious metal. They won't be as highly valued as a gold, silver or even platinum item, but that also means you won't have to spend as much. If you're looking for something a little more high end, consider a tin necklace, bracelet or aluminum novelty cufflinks, like RedEnvelope's Pan Am Cufflinks. Consider one with a diamond setting, which is the modern equivalent of a tin or aluminum present. Tin watches can also be found if you're willing to do a bit of legwork to track one down. Consider having it engraved for added sentimental value.
Some other objects made from tin which may make for suitable gifts include candle holders (given on their own or with candles), picture frames, a vase filled with flowers (daffodils, ideally, so you can continue to build on the 10th anniversary theme), home furnishings and trinkets, or a wall hanging or piece of art made from tin.