Tourmaline on Quartz Bookend, Brazil Snacks as are the fine serrations

as are the fine serrations on the “enamel” portion

Agate forms in the nodule cavities of volcanic rock when silica-rich fluids seep through the volcanic material

a group of woodcarvers of all ages who work in an open-air workshop in Nairobi

” a basic introduction to the subject

Start by learning more about some of your favorite dinosaurs―from Velociraptor to Tyrannosaurus rex―and where you can see the coolest dinosaur skeletons

Tourmaline on Quartz Bookend, Brazil Snacks as are the fine serrationsSchorl, also known as "black tourmaline" or "black schorl", is a black form of tourmaline that often occurs as lustrous prismatic crystals. The crystals can be stubby or elongated and typically feature lengthwise striations. Many schorl crystals have flattened pyramidal terminations. They can also form in radiating, columnar, and stalactitic aggregations, as well as small, needle like inclusions within quartz (tourmalinated quartz) and in massive form.