Hello and welcome to the theme of anything you wish. Here is one kind of stamp I like:
Minerals! Ok it may not by your favorite subject but it is for me. From upper left, and moving clockwise: gyps, or gypsum, amethyst, malachit or malachite, and halite or salt. Gypsum by the way is mined and ground up and used in drywall (sheet rock in some places). Who knew?
This is an older set (Clue: the DDR) with different denominations on each. In fact this gives me an idea. The theme next week will be a set of stamps that really should be pictured together, as the design is continued from one stamp to the next. Any topic. These are se-tenant stamps, correct? Remember I amass stamps, I don't seriously collect them.