Following up on theories that ringwoodite minerals deep within the Earth’s mantle may contain water, a BBC News report says researchers have provided the first direct evidence of this theory.
Diamonds, brought to the Earth’s surface in violent eruptions of deep volcanic rocks called kimberlites, provide a tantalising window into the deep Earth.
A research team led by Prof Graham Pearson of the University of Alberta, Canada, studied a diamond from a 100-million-year-old kimberlite found in Juina, Brazil, as part of a wider project.
They noticed that it contained a mineral, ringwoodite, that is only thought to form between 410km and 660km beneath the Earth’s surface, showing just how deep some diamonds originate.
While ringwoodite has previously been found in meteorites, this is the first time a terrestrial ringwoodite has been seen. But more extraordinarily, the researchers found that the mineral contains about 1% water.
According to the news report, this discovery is important because it solves a 25-tyear-old controversy about deep Earth being wet, dry, or wet in patches. The finding implies that the interior of the planet may store several times the water in the oceans, and demonstrates how hydrogen plays a critical role in the interior processes of the planet, and possibly other planets including Mars.
For more information on ringwoodite:
Tualatin Valley Rock and Gem Club member, Julian Gray, recently released “Minerals of Georgia,” a long-time project with co-author Dr. Robert B. Cook, edited by Jose Santamaria.
Announced in the Examiner and in a public event at the Tellus Science Museum in Atlanta, the new book showcases the geological beauty of the minerals in the state of Georgia, and provides an exceptional educational guide for amateur geologists on the scientific makeup and locations of minerals.
Julian Gray, Executive Director of the Rice Northwest Museum of Rocks and Minerals in Hillsboro, Oregon, previously worked at Tellus Science Museum as its curator. He was a long-time resident of Georgia and intimately familiar with its geology as a geologist, and as a hobbyist from an early age.
Called by many “the bible of Georgia mineralogy to mineral collectors,” this is the updated edition of the 1978 original book. It includes more information on new mineral discoveries, a stronger scientific narrative of each classification, and many more beautiful photographs, many taken by Julian.
He spoke to our group about agates and his upcoming book in August. Julian will be speaking at a variety of events here in Oregon as part of the book tour and promotion. We’ll announce them as they become available.
Congratulations to Julian Gray for the outstanding work he did on the book and the fantastic contribution to mineralogy.
BBC News Science and Environment column reported that scientists have catalogued the largest list ever of rare minerals. The list, published in American Mineralogist, was authored by Dr Robert Hazen, from the Carnegie Institution in Washington DC, and Prof Jesse Ausubel of The Rockefeller University, in New York, and includes more than 5,000 mineral species.
“Scientists have so far tracked down 5,000 mineral species and it turns out that fewer than a 100 constitute almost all of Earth’s crust. The rest of them are rare, but the rarest of the rare – that’s about 2,500 minerals – are only found at five places on Earth or fewer,” Dr Hazen told BBC News.
“And you ask: why study them; they seem so insignificant? But they are the key to the diversity of the Earth’s near-surface environments.
“It’s the rare minerals that tell us so much about how Earth differs from the Moon, from Mars, from Mercury, where the same common minerals exist, but it’s the rare minerals that make Earth special.”
The list includes rare examples including cobaltominite, abelsonite, fingerite, edoylerite, and the extremely rare “vampire-like minerals” that fall apart immediate when wet or the sun shines on them: edoylerite, metasideronatrite, and sideronatrite.
For more information:
For those working in the lapidary arts, we’ve been dazzled by the strength of the minerals and gems we find. The Washington Post announces there is something in nature stronger than diamonds and steel, and unbreakable by bullets.
Currently, the strongest natural material known is the silk of a spider. With this new research, your next tidal pool adventure along the Pacific Northwest coastline might come with a new perspective, and a new respect.
In a study set to come out this month in the Journal of the Royal Society Interface, British researchers announced that the teeth of shelled, aquatic creatures called limpets are the strongest biological material on Earth, overtaking the previous record-holder, spider silk.
The teeth, which are so small they must be examined with a microscope, are composed of very thin, tightly-packed fibers containing a hard mineral called goethite. Limpets use them to scrape food off of rocks, but lead author Asa Barber said humans can adapt the technology to build better planes, boats and dental fillings.
Testing found the mineral material in the snail-like creatures commonly found along tidal pool areas to be nearly flawless in their very thin filaments, reinforcing the structural components, and have a strength of 5 gigapascals, five times that of most spider silks.
The teeth also bested several man-made materials, including Kevlar, a synthetic fiber used to make bulletproof vests and puncture-proof tires. The amount of weight it can withstand, Barber told the BBC, can be compared to a strand of spaghetti used to hold up more than 3,300 pounds, the weight of an adult female hippopotamus.
For information on geothite, see:
The Rice has a great program called Adopt-a-Mineral, allowing the public to donate to the museum by adopting a rock and mineral. The following article is about one of those minerals, fluorite, available for adoption now.
Fluorite (AM 29, AM 30)
Carlo Galeani Napione named the mineral fluorite in the late 1700s. The name derives from the Latin “fleure”, meaning flow, because it is commonly used as a flux. Fluorite is a halide, in which a metal is bonded to one of the halogen elements (fluorine, chlorine, bromine, iodine).
The following images are used courtesy of Wiki Commons.
Fluorite is commonly translucent and found with a vitreous (glassy) luster. It has many colors including, green, purple, yellow, pink, brown and colorless. Its streak (color of the powdered mineral) is white. Fluorite has a hardness of ~4 and is the hardness reference species on Mohs’ scale. It is a brittle mineral, and it will fracture and break along perfect cubic and octahedral cleavage planes. Fluorite usually occurs as cubes, although it can also be found as octahedra (8-faced crystals), and rarely as dodecahedra (12-faced crystals). Sometimes these forms can be found combined in single crystals. When not seen as large crystalline specimens, fluorite is usu-ally massive, or an aggregate of very small cubes. Continue reading “Adopt-a-Mineral at the Rice Northwest Museum – Fluorite”