Many minerals form beautiful crystals, but the most prized of all are gemstones. Uncut gems often look fairly ordinary–like rocks. It's only when they are cut and polished that they obtain the ...

Some gemstones are also minerals, such as that classic rock diamond, but there are some gemstones that aren’t classed as ...

Crystals and gemstones can be more than just beautiful—they can be deadly. Minerals like arsenopyrite, cinnabar, galena, and torbernite carry toxic substances like arsenic, mercury, lead ...