How fitting that the hardest natural substance on Earth is your birthstone! Diamonds are the very essence of fire. In fact, the ancients believed them to be crystallized lightning and slivers of stars.
No matter how (or where) you wear them, you're sure to dazzle with one spectacular light show! Can't afford diamonds? Faux (cubic zirconia) can still mimic the real deal's benefits without costing your whole paycheck.
Another of your gems is bloodstone - or blood jasper - quartz flecked with your metal, iron. While they signify martyrdom (so not Aries!), in India they're thought to be an aphrodisiac. Why not do some experimentation of your own?