What happens when a mineral surface interacts with light is a better question than, “Is this shiny?” Some minerals look quite shiny. Other minerals may have surfaces that look metallic, glassy, pearly, silky, greasy or resinous. Learning to distinguish between…

After you scrape the mineral specimen with a metal implement, you will see a faint line. But is that line necessarily the result of scratching? The metal instrument might be leaving behind tiny flecks of metal or the mineral might…

Hardness on the Mohs scale is determined by the ability of one mineral to scratch another. Hardness is not a measure of a mineral’s strength, weight, toughness, or ease of breaking. The softest mineral used as a reference standard is…

When you set two green minerals side-by-side, they may appear very similar at first glance. But one could be fluorite, while the other is malachite, olivine, or perhaps a weathered mineral with a green outer layer. Because it is easy…