1. Education

Your suggestion is on its way!

An email with a link to:

http://geology.about.com/popular.htm

was emailed to:

Thanks for sharing About.com with others!

Geology: Most Popular Articles

These articles are the most popular over the last month.
Identify Almost Any Rock with This Table
Identify 44 of the most common igneous, sedimentary and metamorphic rock types with this chart.
Use This Master Index of Rock Pictures
My master alphabetical guide to igneous, sedimentary and metamorphic rock pictures.
What to Know About Igneous Rocks
Introducing igneous rocks, first of the three great rock classes (along with sedimentary and metamorphic rocks).
See the Densities of the Most Common Rock Types
Density, or specific gravity, of common rock types.
The Most Common Green Minerals in Nature
A guide to the most common and significant green and greenish minerals.
10 Steps to Help You Identify Any Mineral
Mineral identification starts with picking a good specimen.
What to Know About Sedimentary Rocks
Introducing sedimentary rocks, second of the three great rock classes (along with igneous and metamorphic rocks).
What Is the Most Common Mineral on Earth?
This question has several answers, depending on what a mineral is and what part of the Earth we're talking about.
Why the Earth's Crust Is So Important
The Earth's crust is exceptionally important, and not just because we live on it.
What Is My Blue or Purple Mineral?
A guide to the most common and significant blue and purple minerals.
Identify Typical Minerals with This Master...
My master guide to annotated pictures to help you identify minerals: typical examples of rock-forming, accessory, and rare or notable minerals.
What Makes Metamorphic Rocks Special
Most of the thousands of rare minerals known to science occur in metamorphic rocks, which are formed by great heat and pressure. Introducing
What Is Chemical Weathering?
A short explanation of chemical weathering and carbonation, hydration, hydrolysis and oxidation.
How to Tell the Feldspar Minerals Apart
Feldspar is the commonest mineral in the Earth's crust, but identifying it can be tricky.
What a Black Mineral Is Most Likely to Be
A guide to the most common and significant black minerals.
Why Granite is the Signature Rock of Earth
Granite is the signature rock of the continents. Here are the basics of this important stone.
Sandstone: What It Is and What It Tells Us
Sandstone is sand cemented together into rock.
Where to Look for Rocks and Minerals
Rocks and minerals can be found everywhere, but there is a learning process involved.
6 Things to Know About the Earth's Mantle
A six-part look at the basics of the Earth's mantle, the part between the crust and the core.
Index Fossils: The Key to Telling Deep Time
The concept of index fossils is the very basis of geologic dating.
Igneous Rock Types
The major igneous rock types, plutonic, intrusive and extrusive.
Exfoliation
How big rock domes peel off in shells. Page 6.
Schist
Schist is a major metamorphic rock type from regional metamorphism. Page 15.
Where Are the Greatest Earthquake Threats in...
The United Nations' global map of seismic hazard
What Is My Red or Pink Mineral?
A guide to the most common and significant red and pink minerals.
Fossil Picture Gallery
Pictures of fossils, part of the About.com Geology gallery of images.
Quartz: How to Tell It, Different Kinds, What...
Quartz is essential to the land as we know it.
Serpentinite
Serpentinite is a major metamorphic rock type from regional metamorphism. Page 16.
What Rocks Erode Into: Minerals of the Earth's...
The thousands of minerals known in rocks become a mere handful at the Earth's surface.
Metamorphic Rock Types
The major metamorphic rock types, from regional, contact and mechanical metamorphism.
Sedimentary Rock Types
The major types of sedimentary rocks.
Viewing Earth from on High
Satellite views of Earth's surface make possible geological discoveries never before imagined.
Florida Geologic Map
Geologic map of Florida, part of a set of all 50 states. Page 9.
More Than 50 Different Landforms in Pictures
Find and see geological landforms at About.com Geology.
Georgia Geologic Map
Geologic map of Georgia, part of a set of all 50 states. Page 10.
How to Look at a Rock Like a Geologist
Notes on the most basic operation in geology.
How to Use the Mohs Hardness Scale to Identify...
The 10-mineral Mohs scale of relative hardness is based on which minerals scratch each other.
The Lithosphere in a Nutshell
What you need to know about the lithosphere.
Granite
Granite is one of the major igneous rock types. Page 8.
Siltstone
Siltstone is one of the major types of sedimentary rocks. Page 24.
Slate
Slate is a major metamorphic rock type from regional metamorphism. Page 17.
Mineral Pictures A to Z
A-to-Z list of minerals shown on About.com Geology.
Mechanical Weathering
A short explanation of mechanical weathering.
Phyllite
Phyllite is a major metamorphic rock type from regional metamorphism. Page 13.
Coquina
Coquina is one of the major types of sedimentary rocks. Page 11.
Quartzite
Quartzite is a major metamorphic rock type from regional metamorphism. Page 14.
Measuring Plate Motion
The five ways we track the motion of the lithospheric plates.
Texas Geologic Map
Geologic map of Texas, part of a set of all 50 states. Page 43.
Diorite
Diorite is one of the major igneous rock types. Page 4.
Travertine
Travertine is one of the major types of sedimentary rocks. Page 25.
Silica Tetrahedron Defined and Explained
The silica tetrahedron is the basis of the silicate minerals.
Pegmatite
Pegmatite is one of the major igneous rock types. Page 14.
Gneiss
Gneiss is a major metamorphic rock type from regional metamorphism. Page 6.
What Is My Yellow Mineral?
A guide to the most common and significant yellow minerals.
The Size Divisions of Sediment Particles
The grain sizes of sediments and sedimentary rocks are a matter of great interest to geologists. Here is a guide to sediment grades and grain sizes.
Geologic Maps of the 50 United States
Geologic maps of all 50 U.S. states.
Peridotite
Peridotite is one of the major igneous rock types. Page 15.
What rock is my granite countertop or tile,...
The granites of geology and commerce are quite different.
Volcanic (Extrusive) Rock Types
Photos of the types of erupted igneous rocks.
Scoria
Scoria is one of the major igneous rock types. Page 22.
Gabbro
Gabbro is one of the major igneous rock types. Page 7.
Obsidian
Obsidian is one of the major igneous rock types. Page 13.
Basalt
Basalt is one of the major igneous rock types. Page 3.
Colorado Geologic Map
Geologic map of Colorado, part of a set of all 50 states. Page 6.
Map of Plates and Their Boundaries
Details of the world's major tectonic plates and their boundaries.
Rock Cycle Diagram
The rock cycle as I see it. Geology.
Learn to Read a Geologic Map
Understanding geologic maps starts with topography.
Pumice
Pumice is one of the major igneous rock types. Page 18.
Soapstone
Soapstone is a major metamorphic rock type from regional metamorphism. Page 18.
The Scientific Definition of a Mineral
Minerals meet four criteria, more or less strict.
About Magma
About the molten stuff from which all rocks arise.
Quartz Monzonite
Quartz monzonite is one of the major igneous rock types. Page 20.
Shale
Shale is one of the major types of sedimentary rocks. Page 23.
Fault Types in a Nutshell
The three basic types of fault, with their nomenclature, in a nutshell.
Rhyolite
Rhyolite is one of the major igneous rock types. Page 21.
Porphyry
Porphyry is one of the major igneous rock types. Page 17.
Granodiorite
Granodiorite is one of the major igneous rock types. Page 9.
Andesite
Andesite is one of the major igneous rock types.
Komatiite
Komatiite is a rare and ancient ultramafic lava. Page 11.
Felsite
Felsite is one of the major igneous rock types. Page 6.
Sandstone
Sandstone is one of the major types of sedimentary rocks. Page 22.
Perlite
Perlite is one of the major igneous rock types. Page 16.
About Subduction in Plate Tectonics
Basics of plate tectonics: introduction to subduction.
The Rock-Forming Minerals
A handful of very abundant minerals account for the great majority of the Earth's rocks.
Limestone
Limestone is one of the major types of sedimentary rocks. Page 17.
Greenstone
Grenstone is a major metamorphic rock type from regional metamorphism. Page 8.
What You Should Know about the Earth's Core
The whole Earth on average consists of the same mixture of stuff we see elsewhere in the solar system, but the core has to be iron metal along with some nickel.
Sizes of Tectonic or Lithospheric Plates
Table listing the lithosphere's tectonic plates by oder of size.
What Counts as a Rock to a Geologist?
Everyone knows what a rock is, until you ask what it is exactly.
Pyroxenite
Pyroxenite is one of the major igneous rock types. Page 19.
Graywacke or Wacke
Wacke or graywacke is one of the major types of sedimentary rocks. Page 15.
Tuff
Tuff is one of the major igneous rock types. Page 26.
Minerals with Metallic Luster
Minerals with metallic luster are easy to learn to identify.
Marble
Marble is a major metamorphic rock type from regional metamorphism. Page 10.
Tonalite
Tonalite is a felsic plutonic rock without alkali feldspar. Page 24.
Kimberlite
Kimberlite is the peculiar deep-seated ultramafic rock most famous as the ore of diamonds. Page 10.
Syenite
Syenite is one of the major igneous rock types. Page 23.
Dunite
Dunite is a plutonic rock consisting of olivine. Page 5.
Plate Tectonics Explains How the Earth's...
Start here to learn the basics of plate tectonics.
Rock Gypsum
Rock gypsum is one of the major types of sedimentary rocks. Page 20.
Chert
Chert is one of the major types of sedimentary rocks. Page 7.
Weathering: Details of This Central Geologic...
A short description of weathering.
Brown Minerals
A guide to the most common and significant brown minerals.
Metamorphic Rock Gallery
A spectrum of metamorphic rocks, the pelitic sequence and the basaltic sequence.
Plutonic Rocks
Plutonic rocks defined and explained.
Quartz
Quartz is classified as a rock-forming mineral. Page 9.
State Gemstones of the United States
The 27 official gemstones of 35 states.
Latite
Latite is the extrusive equivalent of monzonite. Page 12.
Migmatite
Migmatite is a major metamorphic rock type from regional metamorphism. Page 11.
Troctolite
Troctolite is one of the gabbroid rocks: igneous, plutonic and mafic. Page 25.
Arkose
Arkose is one of the major types of sedimentary rocks. Page 2.
What to Know Before You Buy a Magnifier
What to think about and look for when you set out to get a nice magnifier.
Holes in Rocks
Geologists have named a variety of holes.
Steno Started Geology with a Few Simple...
Steno (Niels Stensen) first set forth some of the basic principles that all geologists follow.
About Chert
This interesting sedimentary rock has a key role in the geochemical cycle.
The Official State Gemstones, In One List
Thirty-five states have official gems or gemstones, while Montana and Nevada have two. Here they all are, along with the date that they were adopted.
Greenschist
Greenschist is a major metamorphic rock type from regional metamorphism. Page 7.
Peat
Peat is one of the major types of sedimentary rocks. Page 18.
Anorthosite
Anorthosite is one of the major igneous rock types. Page 2.
Rock Salt
Rock salt is one of the major types of sedimentary rocks. Page 21.
Tennessee Geologic Map
Geologic map of Tennessee, part of a set of all 50 states. Page 42.
Utah Geologic Map
Geologic map of Utah, part of a set of all 50 states. Page 44.
QAP Diagram for Plutonic Rocks
QAP ternary diagram showing IUGS classification of phaneritic igneous rocks.
Quartz and Silica Minerals Gallery
Get familiar with quartz.
Earthquakes - The Basics in a Nutshell
Start here for the seismic basics: faults that cause earthquakes, types of seismic waves, damages they cause and more.
North Carolina Geologic Map
Geologic map of North Carolina, part of a set of all 50 states. Page 33.
9 Different Minerals That Are Used as Abrasives
A survey of 9 mineral substances whose properties make them useful abrasives.
New Hampshire Geologic Map
Geologic map of New Hampshire, part of a set of all 50 states. Page 29.
The Great Cascadia Earthquake of 2xxx
Cascadia is America's tectonic version of Sumatra, where the great quake of 2004 occurred.
The Story of Basalt
Basalt has a key role in Earth's tectonic cycle.
Claystone
Claystone is a type of sedimentary rock. Page 8.
Conglomerate
Conglomerate is one of the major types of sedimentary rocks. Page 10.
Fossils: What They Are, How They Form, How They...
Fossils are precious gifts from the geologic past: signs and remains of ancient living things preserved in the Earth's crust.
The Bowen Reaction Series
About this staple of igneous petrology.
Hawaii Geologic Map
Geologic map of Hawaii, part of a set of all 50 states. Page 11.
California Geologic Map
Geologic map of California, part of a set of all 50 states. Page 5.
How to Tell Apart the Granitoid Rocks
How geologists sort out granite from the rocks that look like it.
Dolomite Rock or Dolostone
Dolomite or dolostone is one of the major types of sedimentary rocks. Page 14.
Translate Names Between Gemstones and Minerals
Big list of mineral names and their corresponding gemstone names.
What Is Geology?
The whole of Earth sciences, compressed to a nutshell.
Actinolite
Actinolite is a major amphibole mineral. Page 5.
Diamictite
Diamictite is a messy rock that is not quite conglomerate. Page 12.
South Carolina Geologic Map
Geologic map of South Carolina, part of a set of all 50 states. Page 40.
Fast Links for Real-Time Info on Current...
Directions to information and data from earthquakes as fast as possible.
Is 'Petrified' Different From 'Fossilized'?
What a petrified thing is as opposed to a fossilized thing.
Dinosaur Eggs
Dinosaur eggs for sale at a high-end rock shop. Page 10.
Connecticut Geologic Map
Geologic map of Connecticut, part of a set of all 50 states. Page 7.
Hornfels
Hornfels is a major metamorphic rock type from contact metamorphism. Page 9.
Mylonite
Mylonite is a major metamorphic rock type from mechanical metamorphism. Page 12.
Pennsylvania Geologic Map
Geologic map of Pennsylvania, part of a set of all 50 states. Page 38.

©2016 About.com. All rights reserved.