
Measuring about 150 feet in diameter and weighing 300,000 tons, it entered the Earth’s atmosphere at an altitude of 60 miles where the intense heat of atmospheric friction and compression caused it to glow. As its surface heated to 5000°F. (twice the melting point of iron), it began to melt, vaporize and fragment. Seconds later the remnants of the asteroid, preceded by a monumental atmospheric shock wave, slammed into Earth.
THE CRATER
At the time, no humans were around to witness the impact. But today a quarter-million people each year visit the Arizona Meteor Crater, which is located in northern Arizona 35 miles east of Flagstaff and just south of the “Meteor Crater” exit on Interstate 40.
Seen from a distance, the crater rim appears as a barely noticeable low ridge. But from atop the rim, the view into and across the crater dramatically conveys the cataclysmic nature of the event that created it—a meteoric impact that released the energy of a 20-megaton hydrogen bomb.
This impact instantaneously ejected some 175 million tons of limestone and sandstone, leaving a crater three-quarters of a mile in diameter, a rim rising 200 feet above the surrounding plain, and a crater floor extending 700 feet below the plain. Erosion has since reduced the rim’s height by about 60 feet, while sedimentation has filled in 100 feet of the crater floor.
A WOULD-BE IRON MINE
Denne historien er fra September 2023-utgaven av Rock&Gem Magazine.
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Denne historien er fra September 2023-utgaven av Rock&Gem Magazine.
Start din 7-dagers gratis prøveperiode på Magzter GOLD for å få tilgang til tusenvis av utvalgte premiumhistorier og 9000+ magasiner og aviser.
Allerede abonnent? Logg på

Cleaning & Cracking Géodes, Great and Small
Geodes. From their Latin and Greek origins meaning ‘earth-like,’ the cracking and cleaning of these popular stone eggs is no yolk: those unassuming exteriors can belie wonderful clusters of crystals or banded layers of agate within!

GOLD: PAST, PRESENT & FUTURE
Has Gold Production Finally Peaked?

The Minerals That Made America
Iron, Copper, Lead & Zinc Transformed the United States Into a Major Industrial Power

THE ORDOVICIAN OCEAN OF ST. LEON, INDIANA
Imagine walking through an area filled with millions of fossils just lying there ready for you to pick up and put in your bucket.

A Ring around the World?
\"Ring around the Rosie, a pocket full of posies. Ashes! Ashes! We all fall down!\" So goes the children's nursery rhyme.

IKONS OF THE MINERAL WORLD
Enjoy the following pages from Ikons of the Mineral World Nature's Finest Art by Wayne A. Thompson, Walter E. Donovan, Robert M. Lavinsky, Wendell E. Wilson and Sandor P. Fuss.

Fascinating Fluorite A Beginner & Collector's Favorite
Should you be found, be it working on your collection or walking around a mineral show, humming the song \"My Favorite Things\" with the mineral name 'Fluorite' worked into the lyrics, many of us collectors would totally understand, and probably join in. If that's not the case, let's see if we can make that happen.

ROMANCING THE RUBY
Few words are as packed with meaning as “ruby.” While the word refers primarily to the legendary red gemstone, it is also the preferred adjective for red colors of extraordinary intensity and purity. Its association with wealth and royalty conjures romantic images of kingdoms that once flourished in such historical ruby sources as Ceylon, Siam, Burma and India.

ROYAL SAHARA JASPER
Royal Sahara Jasper was originally discovered in the early 2000s in Northern Africa in the Sahara Desert. During an excursion to Africa, George and Janet Sechler found a piece of rock on the ground that showed similarities to picture jaspers like Biggs or Deschutes.

CLOUDY DAZE
Cloudy Daze is the Novice Design that was selected for the United States Faceting Guild 2025 gemstone faceting competition.