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