|Hawaiian Hot Spot
How did the Hawaiian Islands Form? The power of a moving plate over a stationary hot spot.
Pictures of Opal - A collection of different types of opal from all around the world and Mars too!
Salt Domes - Columns of salt that move upwards because of their low specific gravity.
Fire Opal is a transparent to translucent opal with a yellow, orange or red background color.
Geology.com News is updated several times each week. Read it here or receive email updates.
Rocks - Galleries of igneous, sedimentary and metamorphic rock photos with descriptions.
Geologist Tools - Visit our store for a large selection of field and laboratory tools.
Granite - The intrusive igneous rock that underlies continents and countertops.
Minerals - Descriptions, photos, articles, properties and uses for common minerals.
Shale - The rock that has quickly transformed the oil and gas industry.
Basalt - Most of the ocean basin and part of the continents are underlain by basalt.
Gemstones - Colorful images and articles about diamonds and colored stones.
|The Brewery Rock ?
The Rock Used to Make Beer - Geologists are beer experts and should know about this rock.
||Volcanoes in Space
Extraterrestrial Volcanoes - Earth is not the only solar system body with volcanic activity.
Diamonds - Learn about the properties of diamond, its many uses and diamond discoveries.
Homeowners Insurance usually does not cover the most common geologic hazards.
|Land Below Sea Level
Land Below Sea Level - Did you know that dozens of land locations are below sea level?
Plate Tectonics - Articles, maps, information about plate tectonics and the interior of Earth.
Pavlof Volcano is one of the most active volcanoes in North America and a threat to air traffic.
Ammolite is a fossil and a gemstone. It is shell material from fossil ammonites.
|What Is Earth Science?
What Is Earth Science? The study of Earth and its neighbors in space. Learn more!
Sliding Rocks Mystery - What causes these rocks to slide across a playa in Death Valley?
Obsidian - the volcanic rock that cools so quickly that it becomes a natural glass.
||Oil and Gas
Oil and Gas - Articles about oil and natural gas in the US and around the world.
|Find Minerals & Gems
Find Minerals and Gems - Dozens of sites where you can dig and keep what you find.
Mount Vesuvius - geology, history, maps, facts and more about the Vesuvius eruptions.
||Uses of Gold
The Many Uses of Gold - Unique properties make gold one of the most useful metals.
||Asteroid Impact Map
Asteroid Impact Map - Explore fifty of the most obvious asteroid impact craters on Earth.
Fluorescent Minerals glow with spectacular colors under ultraviolet light.
Troglobites are creatures that have adapted to a permanent life in the darkness of a cave.
Diamond Misconception - Lots of people think that diamonds form from coal. Not True!
Bear Attacks - Knowing how to react to a bear encounter or attack could save your life.
Volcanoes - Articles about volcanoes, volcanic hazards and eruptions past and present.
||Sea Level Rise Map
Sea Level Rise Map - A Google map that shows where flooding will occur as sea level rises.
Fossils - Learn about fossils and fossil discoveries around the world.
Emerald is the most popular green gemstone in the United States and most of the world.
100+ Gems - Photos of over 100 beautiful gems ranging from the popular to the obscure.
||Gems from Space
Extraterrestrial Gems - A number of materials from space are used as attractive gems.
||Lunar Rift System
Lunar Rift System? Gravity maps revise the geologic history of the near side of the moon.
||Google Earth - Free
Free Google Earth software allows you to browse seamless world satellite images. Free.
Rock Art - People have been marking on rocks for thousands of years.
Tallest Tsunami - A wave with a run-up height of 1720 feet occurred in Lituya Bay, Alaska.
Labradorite is a feldspar mineral that sometimes exhibits an iridescent play-of-colors
Turquoise - A blue to bluish-green gem material that has been used for over 6000 years.
|Crater of Diamonds
Crater of Diamonds - The only diamond mine in the world where you can be the miner.
Astronomy - Fantastic images and articles about solar system and deep-space astronomy.
Teacher Resources - K-12 resources for teaching about earth science.
||Cave of the Hands
Cave of the Hands is a cave where ancient people painted hands about 9000 years ago.
|Facts About Copper
Facts About Copper - Information about copper uses, production, resources and more.
Volcanic Explosivity - Rating volcanic eruptions based upon the volume of tephra ejected.
Most Powerful Eruption of the 20th Century - One hour later, the blast was heard in Juneau.
||What is LNG?
What is LNG? The use of LNG as an energy source is growing rapidly. Learn more about LNG.
|US Diamond Mines
US Diamond Mines - Did you know that diamonds have been found in the United States?
||Rare Earth Elements
Rare Earths - Special materials used in electronics, defense, medical & many other products.
||What is a Maar?
What is a Maar? The second most common volcanic landscape feature on Earth.
Dowsing is a method used to find underground water that is rejected by most geologists.
|Ruby and Sapphire
Ruby and Sapphire are the 2nd and 3rd most popular colored stones in the United States.
Meteorites - Rocks that were once parts of planets or large asteroids.
Pumice is a rock formed during explosive volcanic eruptions. It has a wide variety of uses.
Largest Earthquake ever recorded - Magnitude 9.5. Chile, 1960.
Soapstone is a metamorphic rock with properties that make it suitable for a variety of projects.
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.
||What is Geology?
What is Geology? - The study of Earth materials, structures, processes and life over time.
Metals are important mineral products used in manufacturing and construction projects.
||San Andreas Fault
The San Andreas Fault - A feature that separates the Pacific and North American Plates.
Organic Gems are gems formed from or by plants or animals. They might also be fossils.
||Watch out for Ticks!
Ticks are a problem for geologists in some areas. Learn to recognize and avoid them.
Iolite is the gem variety of the mineral cordierite. An alternative to sapphire and tanzanite.
Sand is a diverse material. This gallery includes photos of sand from around the world.
Mount Etna - The most active volcano in Europe continues an eruption that started in 2001.
||USA Landslide Map
Landslide Incidence Map - A USGS map showing landslide incidence in the United States.
Petrified Wood is a fossil that forms when dissolved material preciptates and replaces wood.
Horizontal Drilling has opened new resources and significantly improved productivity.
Garnet is best known as a red gemstone. It occurs in any color and has many industrial uses.
Tallest Mountain - Everest has rivals in tallness, altitude and distance to the center of Earth.
|Geologic Time Scale
Divisions of Geologic Time - USGS time scale with unit names and age estimates.
||Types Of Eruptions
Types of Volcanic Eruptions - A description of the most common eruption types.
Largest Desert - The Sahara is huge but two polar deserts are larger.
||What is a Geyser?
Photos of Geysers from around the world with information about height, eruption interval, more.
Ametrine is a bicolor quartz (amethyst + citrine) and a gemstone of growing popularity.
Salt Glaciers are masses of salt that flow downslope under their own weight.
Sunstone is a gem feldspar with aventurescence caused by light reflecting from platy inclusions.
||The Acid Test
The Acid Test - Geologists use dilute hydrochloric acid to identify carbonate minerals.
Frac Sand - The amount of frac sand produced in the USA is up by over 300% since 2009.
Hydraulic Fracturing - Increases well yield by fracturing the reservoir rock with fluid injection.
Chatoyant Gems look like the eye of a cat. They have a line of light that moves across the stone.
||Coal Close Up
Coal Through a Microscope - Coal is more than a black rock. It is THE most interesting rock.
Largest Volcano - That title is shared by Tamu Massif, Mauna Kea and Ojos del Salado.
Oil Sands contain oil in the form of bitumen. A major oil resource that can be difficult to produce.
||Uses of Marble
The Uses of Marble are numerous and diverse. You will be surprised by how it is used.
California Earthquake Maps - A collection of isoseismal maps for earthquakes in California.
Methane Hydrate deposits contain more fuel value than all other fossil fuels combined.
||Rocks on Mars
Rocks on Mars - Many of the rocks found on Mars are not very different from Earth rocks.
||Eagle Ford Shale
Eagle Ford Shale - One of the most prolific producers of oil and gas in the United States.
||Huge Diamond Deposit
The Largest Diamond Deposit in the world could be under Popigai Crater in Russia.
Mohs Hardness Scale is a set of reference minerals used for classroom hardness testing.
Mineraloids are amorphous naturally-occurring inorganic solids that lack crystallinity.
Rock Glaciers - Masses of rock, ice, snow, mud and water that slowly flow down slope.
||Great Rift Valley
The East Africa Rift System - The extensive fault system that is tearing Africa apart.
The Host Rock of Diamonds - Diamonds are found in Kimberlite, a variety of peridotite.
||What Is The Moho?
What Is The Moho? Learn about the Mohorovicic Discontinuity - the mantle/crust boundary.
Hematite - the most important ore of iron and a source of mineral pigment since prehistory.
How Do Snowflakes Form? They start as tiny mineral crystals but they might not reach the Earth.