Volcanic Obsidian
Volcano Terms and Definition


World of the Microscope
Science & Experiments Series

Fascinating, hands-on introduction to using microscopes, this book is packed with exciting projects which reveal the amazing detail of the world around us.

The colors in obsidian result from the oxidation state of the chemical elements within the tiny minerals that are finely dispersed in the glass. Black color results chiefly from magnetite, Fe304. If the obsidian is highly oxidized, then the glass may contain hematite, which provides a reddish hue. Variations in the oxidation state of the iron (Fe) varieties imparts a slight greenish hue. Some obsidian is banded, a consequence of oxidation on a flow surface being folded into the lava as it continues to move.
Obsidian

Obsidian is dense volcanic glass, usually rhyolite in composition and typically black in color. Compared with window glass, obsidian is rich in iron and magnesium; tiny (<.005 mm) crystals of iron oxide within the glass cause its dark color. 

Obsidian is often formed in rhyolite lava flows where the lava cools so fast that crystals do not have time to grow. Glass, unlike crystals, has no regular structure and therefore fractures in smooth conchoidal (curved) shapes. The intersections of these fractures can form edges sharper than the finest steel blades. For this reason, obsidian was used by many native cultures to make arrowheads and blades.


Digtal Microscope

Volcano Glossary



NOVA - In the Path of a Killer Volcano
The scientists who remain behind- and see some astonishing footage of the world's largest volcanic eruption in 80 years. Local tribes people were the first to see the signs. "There was a flash of light from the sky"

National Geographic - Volcano
The most dazzling but destructive natural force on earth. Massive volcanic eruption can turn day into night, releasing the power of an atomic blast, spewing toxic avalanches of lava, gas, and ash. National Geographic Video transports you to some of the world's most notorious volcanoes

National Geographic's Restless Earth Collection
Asteroids Deadly Impact Volcano Nature's Fury. The devastating powers of earthquakes, hurricanes, tornadoes, volcanoes and other earth-shattering forces of nature in dramatic scenes of destruction and inspiring human courage captured by the acclaimed filmmakers of National Geographic

Super volcano - It's Under Yellowstone. And It's Overdue

A subterranean sea of molten lava that scientists are sure will burst through the Earth's crust it's just a question of when. And if the resulting super-volcanic eruption is anything like the last one on earth which plunged the world into darkness for six years, tipped us into the last Ice Age and reduced the human population to just 2,000 people we're in for one explosive ride

Lava Flows and Lava Tubes
40-minute video uses spectacular and unusual footage of erupting volcanoes from Hawaii and around the world to explain the features found in many of our volcanic national parks and monuments, and to show how they form. It presents up-to-date scientific ideas about lava flows: how they move, how they change, and how they create lava tubes

Fire Mountain: The Eruption and Rebirth of Mount St. Helens
Two hundred and thirty square miles leveled in moments Five hundred and forty million tons of ash and volcanic rock exploded twelve miles high One cubic mile of earth blasted from the crest of one of the world's most beautiful snowcapped domes Captured in rare and spectacular aerial photography and survivor's own words and pictures, witness the terrifying fury of the worst volcanic disaster in American history

Ring of Fire - IMAX
The Closest You'll Ever Get to a Volcano Originally filmed in IMAX Ring of Fire takes you heart stopping close to the great circle of volcanoes and seismic activity that rings the Pacific Ocean. This film has been seen by millions of people. The story of these immense volcanic forces and the half a billion people that coexist with them every day around the fiery boundary of the Pacific Rim

Savage Earth

Waves of Destruction
Out of the Inferno
Restless Planet
Hell's Crust
From the legendary fury of Mt. Vesuvius to the devastating convulsions of Kobe, Japan, Savage Earth tells the stories of these great natural disasters, the scientists who struggle to understand and predict them, and the people whose lives are forever changed by their merciless force



Baby Einstein Play Gyms
Let the Baby Einstein Seek and Discover Activity Gyms stimulate and inspire your baby. The soft mat provides a comfortable place for baby to rest, while bright colors, fun characters and a variety of toys provide an enriched environment for baby to explore.

Young Learners Microscopes
Expose your child to the fascinating world of natural specimens as you examine an arachnid, a crustacean and other insects up-close. Grades K & up. Fully functioning microscope makes learning fun!

Elenco Electronics
Electronic Snap Circuits by Elenco is an award-winning toy for budding engineers eight years old and above. For students who are already learning about electronics in school, this set creates a hands-on experience that makes for more fun than reading about how these things work in a textbook.



Learning Resources Gears! Gears! Gears! Oogly Googly

Includes motor and hand control (with forward/reverse switch), gears, springs, connecting blocks, two claws, and three eyeballs. Starting with the motor pack, add the pieces together according to the instructions or follow your own mad scientist ideas to create endless mayhem. Can be used alone or with other Gears! Gears! Gears! sets.

Learning Resources Gears! Gears! Gears!

Great toy to help open up the world of "how things work" for younger kids. Inspires imaginative play, problem solving, and cause & effect thought processes. Gear up for hours of colorful action with Gears! Gears! Gears! enables children to create hundreds of three-dimensional construction possibilities. Set features plastic gears, connectors and interlocking bases packaged in a giant storage tub with an Activity Guides.

Gears! Gears! Gears! Boogie Buddy Motorized Sets

Challenge kids' mechanical reasoning skills while encouraging creativity and gross motor coordination through building and movement. Color-coding makes it easy for children to follow building instructions for three different models. They can also create their own model. Compatible with all other Gears! Gears! Gears! Sets, sold separately.


Source:
U.S. Department of the Interior