Picasso Chert from Burro Creek, AZ, collected by Arizona State University Geology Professor and Author Stan Celestian.
In the March 2020 issue of Rock & Gem, in my article entitled Cherishing Chert: A Mother Rock for the Ages, I discussed the ancient origins of chert as a building block of Earth’s early ocean basins. I illustrated my narrative with two famous formations, the Kaibab Cliffs of the Colorado Plateau and the banded iron formations (BIFs) of Mingus Mountain in the Black Hills region of north-central Arizona.
These ancient deposits crop out at the top of Mingus Mountain and are the source of the hematite and jasp-chert BIFs of the Verde Valley. Chert is a name that is often used interchangeably with another impure opaque variant of chalcedony known as jasper thus the use of the term “JaspChert.” The unique rocks described in this article combine distinguishing characteristics of both varieties and constitute minerals of the chert complex.
CHERT-BASED MINERALS COMBINE ALL ROCK CLASSIFICATION CATEGORIES
The chert-based Kaibab and BIF rocks containing calcium and magnesium-carbonate and iron oxides constitute just a few chert minerals commonly found in Arizona and are now known worldwide. These mineralized rocks establish the complex of chert formations that encompass Earth’s fundamental stratigraphic units as defined by the Geologic Time Scale, and the study of physical geology.
Denne historien er fra July 2021-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
Denne historien er fra July 2021-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
THE BRIGHT SIDE OF VOLCANIC ROCK
As a mineral resource, volcanic rock is decidedly short on glamour.
The Other Copper Minerals
12 Lesser-known Collectible Species
MINERAL COLLECTING -AND ROCK & GEM
Evolving Together FOR 54 YEARS
Gemstone Trends
A Look Back at 2024 & What to Expect in 2025
How to Make a GEM BEAD NECKLACE
No Lapidary Experience Needed!
Framing Nature's Art
Faceting Rutilated Quartz for Beginners
BEDAZZLED BLUE SEAM AGATE
More than several centuries ago, mining was the profession most often seen as befitting of men.
ROCK & GEM FIELD GUIDE:
Spinel is a captivating gemstone with a rich history of being mistaken for gems like ruby and sapphire.
SNAKE SCALE DROP 1.5:1
This Faceting Focus is revisiting the briolette gemstone design because of its popularity with independent and hobby gemstone faceters.
STONE CHIC
How Earth-Inspired Decor Brings Comfort to our Home