Olivine - Abundant in Earth*s mantle. A constituent of meteorites. The gem peridot.
Coal Through a Microscope - Coal is more than a black rock. It is THE most interesting rock.
World*s Largest Diamonds Records for the largest rough, faceted and carbonado diamond.
Talc is a soft mineral used in cosmetics, paper, paint, ceramics and many other products.
Minerals - Descriptions, photos, articles, properties and uses for common minerals.
The Unsung Mineral Hero - and the commodity upon which almost everything is built.
100+ Gems - Photos of over 100 beautiful gems ranging from the popular to the obscure.
The Doorway to Hell is a flaming sinkhole seeping natural gas that has been burning for decades.
Plate Tectonics - Articles and maps about plate tectonics and the interior of Earth.
Homeowners Insurance might not cover earthquake, hurricane and other geohazard damage.
Rocks - Galleries of igneous, sedimentary and metamorphic rock photos with descriptions.
Lapis Lazuli - a metamorphic rock and the most popular blue opaque gemstone in history.
Rock Salt is a sedimentary rock composed of the mineral halite. It has many uses!
Free Google Earth software allows you to browse seamless world satellite images. Free.
Know the Rules before removing rocks, fossils or minerals from public or private property.
Wall Maps - Wall maps of the world, continents, states and the USA.
Grape Agate is a popular mineral specimen with the color and the shape of a bunch of grapes.
Granite - The intrusive igneous rock that underlies continents and countertops.
Emerald is the most popular green gemstone in the United States and most of the world.
Rhyolite An extrusive igneous rock with a high silica content, produced from granitic magma.
Birthstones are gems assigned to the month of a person*s birth. They are popular gifts in the U.S.
Diamonds - Learn about the properties of diamond, its many uses, and diamond discoveries.
Obsidian - the volcanic rock that cools so quickly that it becomes a natural glass.
Gemstones - Colorful images and articles about diamonds and colored stones.
Cave of the Hands is a cave where ancient people painted hands about 9000 years ago.
Rocks on Mars Many of the rocks found on Mars are not very different from Earth rocks.
Chalcopyrite - The most important ore of copper for over five thousand years.
Waterproof Paper - Don't take chances with your field notes and maps. Use waterproof paper.
Types of Maps - Explore some of the most popular types of maps that have been made.
Types of Volcanic Eruptions - A description of the most common eruption types.
The Rock Used to Make Beer - Geologists are beer experts and should know about this rock.
Rock & Mineral Kits The best way to learn about rocks and minerals is with specimens!
Hand Lens A 10-power folding magnifier in a metal case. A frequently used lab and field tool.
Meteorites - Rocks that were once parts of planets or large asteroids.
The Green River Formation is one of the most famous rock units in the world for its fossils.
Ilmenite - The primary ore of titanium and source of most titanium dioxide.
Crater of Diamonds - The only diamond mine in the world where you can be the miner.
Fire Opal is a transparent to translucent opal with a yellow, orange or red background color.
Quartzite is metamorphic rock formed when sandstone is subjected to heat and pressure.
Hardness Picks - Test for hardness with precise and easy-to-use hardness picks.
Pictures of Opal - A collection of different types of opal from all around the world and Mars too!
Geology Books - A variety of books for reference, field trips, reading and more.
Volcanoes - Articles about volcanoes, volcanic hazards and eruptions past and present.
Debris Flows are moving masses of loose mud, sand, soil, rock and water.
Portable UV Lamp - Short and long wave UV for fluorescent mineral viewing.
The Uses of Marble are numerous and diverse. You will be surprised by how it is used.
Bear Attacks - Knowing how to react to a bear encounter or attack could save your life.
Extraterrestrial Gems - A number of materials from space are used as attractive gems.
Labradorite is a feldspar mineral that sometimes exhibits an iridescent play-of-color.
Gifts That Rock - What are the most popular gift items in the Geology.com store?
Copper is a metal used in coins, electronics, pipes, wiring, motors, alloys and many other products.
Spatter Cones are small, steep, volcanic cones built of welded basaltic lava.
Geodes look like ordinary rocks on the outside but can be spectacular inside!
Andalusite is a metamorphic mineral and a strongly pleochroic gem material.
Blue Flames and the largest highly acidic lake in the world at Kawah Ijen Volcano.
Fool*s Gold is a name used for pyrite when its brassy color fools people looking for gold.
Rare Earths - Special materials used in electronics, defense, medical & many other products.
Geology Tools - Rock hammers, field bags, hand lenses, maps, hardness picks, gold pans.
Rhodochrosite - a manganese mineral used as an ore, a pink gem and an ornamental stone.
Field Courses - Over 80 field courses for undergraduate geology students.
Diamond Misconception - Many people think that diamonds form from coal. Not True!
Where Are the Canary Islands? Off the northwest coast of Africa, 60 miles west of Morocco.
Fluorescent Minerals and rocks glow with spectacular colors under ultraviolet light.
Rock Tumblers - All about rock tumblers and rock tumbling. Read before you buy a tumbler.
Ruby and Sapphire are the 2nd and 3rd most popular colored stones in the United States.
Teacher Resources - K-12 resources for teaching about earth science.
Rock Art - People have been marking on rocks for thousands of years.
Ticks are a problem for geologists in some areas. Learn to recognize and avoid them.
Mineral Rights - Who owns the minerals under your land? Who wants to buy them?
Expansive Soil causes more damage than floods, hurricanes & tornadoes combined.
Tallest Tsunami - A wave with a run-up height of 1720 feet occurred in Lituya Bay, Alaska.
Ethiopian Opal - The new opal heavyweight that might give Australia a run.
Turquoise - A bluish-green gem material that has been used for over 6000 years.
What Is The Moho? The Mohorovicic Discontinuity is the mantle/crust boundary.
Tanzanite was unknown until a few decades ago but it has erupted into wide popularity.
Corundum is the third hardest mineral. It is also the mineral of ruby and sapphire.
Morganite is an orange to pink gemstone, a variety of beryl, that is growing rapidly in popularity.
Cinnabar - the only important ore of mercury. Used in pigments until its toxicity was realized.
Largest Earthquake ever recorded - Magnitude 9.5. Chile, 1960.
Sand is a diverse material. This gallery includes photos of sand from around the world.
Citrine is the transparent variety of quartz with a yellow to orange to reddish color.
Gold Pans and Panning Kits - classifiers, snuffer bottles. Learn how to pan for Gold.
Mohs Hardness Scale is a set of reference minerals used for classroom hardness testing.
Helium is a byproduct of the natural gas industry. Its most important use is in MRI.
Crystal Habit is the external shape displayed by a crystal or an aggregate of crystals.
The Science of Fireworks Learn how the colors and shapes are created.
Zircon is the primary ore of zirconium and a gemstone that is available in many colors.
Largest Hurricanes Are they determined by wind speed, value of damage, most deaths?
Names Used for Great Britain, British Isles, United Kingdom, and Ireland. What they mean.
Peridotite is a chromite host rock, a source of diamonds and a possible carbon dioxide sink.
Map of the Oceans - showing the Atlantic, Pacific, Indian, Arctic, and Southern Oceans.
What Is Luster? Luster is the light-reflecting characteristics of a mineral specimen.
Mars Meteorites Mars rovers have found dozens of meteorites while exploring the red planet.
The East Africa Rift System - The extensive fault system that is tearing Africa apart.
Colored Diamonds are diamonds with a noticeable body color. They can sell for over $1M/carat.
What is Geology? The study of Earth materials, structures, processes and life over time.
The Acid Test - Geologists use dilute hydrochloric acid to identify carbonate minerals.
The Many Uses of Gold - Unique properties make gold one of the most useful metals.
Mineraloids are amorphous naturally-occurring inorganic solids that lack crystallinity.
Ant Hill Garnets - tiny gems that ants haul to the surface and discard on their anthill. Honest!
Gem Silica is a blue chalcedony colored by copper. It is the rarest and most valuable chalcedony.
Tallest Mountain - Everest has rivals in tallness, altitude and distance to the center of Earth.
Topo Maps - The DeLorme Atlas is an entire state of topo maps in one convenient book.
Petrified Wood is a fossil that forms when silica replaces and infills the cavities of wood.
Largest Volcano - That title is shared by Tamu Massif, Mauna Kea and Ojos del Salado.
Novarupta - The most powerful volcanic eruption of the 20th century occurred in the U.S.A.
Pyroxene Minerals are a group of chain silicate minerals found in igneous and metamorphic rocks.
Hawaii*s Next Island could be growing in the Pacific Ocean right now. Its name is Lo*ihi.
Phytoplankton Blooms are caused by an explosive growth rate of plankton in surface waters.
10 Gemmy Facts About Spinel - Is spinel the world*s most overlooked gem?
Sliding Rocks Mystery - What causes these rocks to slide across a playa in Death Valley?
Tourmaline - an extremely colorful mineral and gem material.
Cinder Cones are the smallest, simplest, and most common type of volcano.
Hematite - The most important ore of iron. A source of mineral pigment since prehistory.
Agnes Orinda Plus Size Denim Dresses for Women Ruffle Hem Casual - this lake has more lightning than any other place in the world.
What is the San Andreas Fault? Map, photos and description of the fault.
US Diamond Mines - Did you know that diamonds have been mined in the United States?
Chalk is a variety of limestone formed from fine-grained marine sediment known as ooze.
Herkimer Diamonds Doubly-terminated quartz crystals used as specimens and gems.
What is a Maar? The second most common volcanic landscape feature on Earth.
Charoite is a purple silicate mineral, found only in Russia, used as a gem material.
What is a Geyser? Photos and information about geysers in many parts of the world.
Lightning Strikes Map by NASA shows the worldwide distribution of lightning activity.
Volcanic Explosivity - Rating volcanic eruptions based upon the volume of tephra ejected.
Shale - The rock that has quickly transformed the oil and gas industry.
Azurite - Used as an ore of copper, a pigment, ornamental stone and gem material.
California Earthquake Maps - A collection of isoseismal maps for earthquakes in California.
Range of Bear Species - Where you might encounter different types of bears.
Coquina - A porous limestone composed almost entirely of fossil debris.
What Is Earth Science? The study of Earth and its neighbors in space. Learn more!
Storm Surge can be the most damaging and deadly aspect of a hurricane.
Utica Shale is a major source of oil, natural gas and natural gas liquids in PA, OH and WV.
Solar System Volcanoes - Earth is not the only location of volcanic activity.
Deepest Point in the Ocean The deepest point in the ocean is in the Mariana Trench.
How Are Hurricanes Named? There is a plan for naming tropical storms.
Angel Falls in Venezuela is the tallest waterfall in the world - it is 3212 feet tall.
Mined in America - Small mines in the United States produce a diversity of beautiful gemstones.
Soapstone is a metamorphic rock with properties that make it suitable for a variety of projects.
How did the Hawaiian Islands Form? The power of a moving plate over a stationary hot spot.
Mount Etna - The most active volcano in Europe continues an eruption that started in 2001.
Mount Vesuvius - geology, history, maps, facts and more about the Vesuvius eruptions.