Photos and information about 80 common rock-forming, ore and gemstone minerals from around the world.

Home » Minerals » What is a Mineral? What are Minerals? Minerals are the foundation of the construction, manufacturing and agricultural industries. Article by: Hobart M. King, PhD Mineral …

The Most Abundant Minerals in Earth's Crust: Known as the "common rock-forming minerals", they are minerals present at the time of a rock's formation and are important minerals in determining the …

Mohs - Vickers hardness comparison: This chart compares the hardness of index minerals of the Mohs hardness scale (an integer scale) with their Vickers hardness (a continuous scale). Mohs hardness is …

Fluorescent minerals: One of the most spectacular museum exhibits is a dark room filled with fluorescent rocks and minerals that are illuminated with ultraviolet light. They glow with an amazing …

Garnet Physical and Chemical Properties The most commonly encountered minerals in the garnet group include almandine, pyrope, spessartine, andradite, grossular, and uvarovite. They all have a vitreous …

What is the Acid Test? To most geologists, the term " acid test " means placing a drop of dilute (5% to 10%) hydrochloric acid on a rock or mineral and watching for bubbles of carbon dioxide gas to be …

Articles about gemstones written by a GIA Graduate Gemologist. Each article includes photos and information about the gem's physical properties and geologic origin.

Home » Metals » REE - Rare Earth Elements REE - Rare Earth Elements and their Uses The demand for rare earth elements has grown rapidly, but their occurrence in minable deposits is limited. Article …

Associated minerals include: smithsonite, sphalerite, cerussite, anglesite, and galena. Diagnostic properties in hand specimens are its crystal habit, hardness, specific gravity, and its effervescence …