I was born in October, which means my birthstone is an opal. The alternative to opal is tourmaline, which I would prefer hands down. It isn't necessarily that I do not find opals pretty or the like, but more so because it is weaker compared to a tourmaline. There are plenty of stones that I find pretty, but I would sooner get something that is stronger. For instance, I think iolite is gorgeous, but isn't a particularly strong mineral, though fairly strong compared to others. I find the history of the iolite even more enticing in owning one, as it is regarded as the viking stone, where shaved pieces of iolite would be utilized as a sort of solar filter in the yesteryears while the nords still roamed the seas, using the Sun to navigate. I like paler, more subtle colored stones myself, such as iolite, kunzite, and aquamarine. Purples, pinks, and greens are my favorite colors when it comes to a stone though and with tourmaline, you have essentially an endless variety in color and shade.