Jeff
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likelyactinolite.bsky.social
Jeff
@likelyactinolite.bsky.social
24 followers 52 following 8 posts
Graduate Gemologist, B.S. in Earth Sciences, minerals and rocks ❤️
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Reposted by Jeff
geologytime.bsky.social
Pineapple opal—also known as ananas opal—is an exceptionally rare variety of precious opal found exclusively in the White Cliffs region of New South Wales, Australia.
#opal #gems
www.geologyin.com/2016/08/gorg...
Pineapple Opal – Geology In
Pineapple opal —also known as ananas opal —is an exceptionally rare variety of precious opal found exclusively in the White Cliffs regi...
www.geologyin.com
September 8, 2025 at 5:15 PM
Reposted by Jeff
aferguson.bsky.social
Stunning sky + stunning geologic formations = #Stunday
Panorama Trail in Kodachrome Basin State Park, #Utah
#photography #hiking #geology #rocks
A sky full of lowering clouds, some dark and some puffy casts shadows over a long ridges of red and gray sandstone dating from the middle Jurassic Period (180 million years ago) to the Cretaceous Period (95 million years ago). In the foreground the trail winds through scrub, pinion pines, and utah juniper trees.
September 14, 2025 at 12:51 PM
Reposted by Jeff
nadwgab.bsky.social
252 of #365Minerals 🧪⚒️

Opal:
- Hydrated form of silica
- A mineraloid (has an amorphous structure)
- Consists of silica spheres which diffract light, producing a rainbow effect
- Wood can become opalised during fossilisation
- Its name likely comes from the Sanskrit "उपल/upala" (stone) #minerals
A cut and polished slice of petrified wood. It's a light beige colour with concentric rings and radial patterns with a black centre. It looks a bit like a less evil version of the Eye of Sauron. Label text: Wood opal, polished slice of fossil oak tree. Clover Creek, Idaho. Specimen on display in the Natural History Museum, London. Blue to milky white precious opal in a grey iron nodule. The sun is shining on the specimen so there are colourful flashes of red, green and blue in it. From Queensland, Australia. Specimen on display in the Natural History Museum, London.
September 9, 2025 at 9:54 AM
Reposted by Jeff
aferguson.bsky.social
It's #WaterfallWednesday so here's one of the iconic #Iceland waterfalls: Svartifoss, flowing over a cliff of columnar basalt. #photography #waterfalls #geology.
Svartifoss, 65 feet (20 meters) tall is one of the chief attractions in the Skaftafell area of Vatnajökull National Park. At the top, the basalt columns are broken off several layers deep making them look a little like an upside down pipe organ.
September 10, 2025 at 12:17 PM
Reposted by Jeff
womensartbluesky.bsky.social
'Californian Morning' (mid 20thc) by US artist and printmaker Emmy Lou Packard (1914-1998) #WomensArt
Print featuring a shoreline with plants, a blackbird and insects in silhouette in front of sea and a glowing red sun
August 10, 2025 at 12:49 PM
Reposted by Jeff
geologytime.bsky.social
Watermelon Tourmaline is a lithium-rich tourmaline mineral, characterized by its notable concentric color zoning. This zoning typically consists of a pink or red core, colored by manganese, surrounded by a green outer rim, colored by iron or chromium.
www.geologyin.com/2021/07/wate...
What is Watermelon Tourmaline (Photos) – Geology In
Watermelon Tourmaline is a distinct variety of elbaite , a lithium-rich tourmaline mineral, characterized by its notable concentric color ...
www.geologyin.com
June 12, 2025 at 7:43 PM
Reposted by Jeff
ajsteinmetz.com
The earliest evidence for life is a 4.1 billion years old zircon crystal grain with encased graphite sporting a high carbon ¹²C/¹³C isotope ratio. Life preferentially uses the lighter ¹²C atom in biological processes. #Science #Biology #Geology 🧪

See: doi.org/10.1073%2Fpn...
Transmission X-ray image of RSES 61-18.8 with graphite indicated. (Inset) Raman spectra for the top inclusion and for an epoxy “inclusion” from another investigated zircon. The broadened “D-band” at ∼1,400 cm−1 indicates disordered graphite (39); C–H stretch bands at ∼2,800–3,100 cm−1 (39) are observed in epoxy but not graphite.
June 1, 2025 at 2:17 PM
Reposted by Jeff
stressrelated.bsky.social
For geologists: I remember reading Russian geology papers and maps in the early 90s, and being struck by the absence of plate tectonics. It wasn't accepted in Soviet Russia.

(I would love to see a historian of science talk about the rejection of plate tectonics in the Soviet Union.)
petergleick.bsky.social Peter Gleick @petergleick.bsky.social · May 31
There are 2 previous historical cases of countries destroying their science and universities, crippling them for decades: Lysenkoism in the USSR and Nazi Germany. The Trump administration will be the 3rd.
It's not just budgets but research, institutions, expertise, and training the next generation.
Graphs showing 25 years of budgets for the National Institute of Health, NASA, and the NSF. In all cases, the proposed budget for next year is far, far below any year of the previous quarter century.
May 31, 2025 at 1:53 PM
Reposted by Jeff
geologytime.bsky.social
Incredible Double Sided Pattern Koroit Boulder Opal.

Photo ©️ Wild.Opals
#OPAL
May 26, 2025 at 4:14 PM
Reposted by Jeff
geologytime.bsky.social
Natural Welo Opal Raw, from Ethiopia

Photo by: BigStargems

#opal #gems
May 17, 2025 at 4:27 PM
Reposted by Jeff
geologytime.bsky.social
Matrix opal refers to opal that formed pervasively within the structure of its host rock. It fills the pores, voids, or spaces between the grains of this surrounding rock—typically called the matrix.

Photo by: Brisbane Opal Museum
#opal
May 12, 2025 at 4:51 PM
Reposted by Jeff
johnpelwood.bsky.social
A colleague emailed me today to flag the fact that the superb Fourth Circuit Judge J. Harvie Wilkinson ended a quotidian insurance opinion with an unusually introspective conclusion.
April 24, 2025 at 2:47 PM
Reposted by Jeff
catsofyore.bsky.social
Two unrelated postcards in my collection that tell a story together. 🤕
Two vintage postcards side by side. On the left a color illustration of black cat with a bandage around its head grimaces, “You ought to see the other fellow”. On the right a black and white illustration of a black cat with bandaged head, limbs and tail says “Stung! But you should have seen the other fellow”.
April 15, 2025 at 1:19 AM
likelyactinolite.bsky.social
January 5, 2025 at 4:37 AM
Reposted by Jeff
gkiseki.bsky.social
Geology of Katsurajima Island (Dike)
#Japan #geology #photography #outcrop

Katsurajima Island in Shimane Town, Matsue City, Shimane Prefecture, Japan, is known for its geology formed by andesitic to rhyolitic lava that erupted underwater about 15 million years ago (Middle Miocene epoch).
This location is renowned for the various lava formations that can be observed. This photograph captures a dike cutting through the lava. Upon close inspection of this dike, one can observe that while the deeper parts maintain a dike-like structure, the shallower sections show magma transforming into an auto-brecciated state upon contact with seawater. Such transitions can be observed here. The central pointed hill-like structure is the dike, while the areas on both ends of the photo are lava domes penetrated by the dike. The boundary between the two is marked by a chilled margin several centimeters thick, and they can be easily distinguished by the differences in their well-developed joint systems.
December 6, 2024 at 5:33 PM
Reposted by Jeff
nadwgab.bsky.social
A Jurassic (151.5 million year old) sphenodont in Solnhofen limestone. Sphenodonts are lizard-like reptiles. When I saw this specimen back in mid 2017, its label said it was an undescribed new species

On display in the Bürgermeister-Müller-Museum in Germany
#fossils #geology #FossilFriday ⚒️🧪
A slab of Solnhofen limestone with a fossilised skeleton of a sphenodont, a lizard-like reptile with a long tail. Its posture makes it look like it's crawling up the slab. The slab is lit from above which gives it a yellowish glow.
December 6, 2024 at 12:19 PM
Reposted by Jeff
jeffontherock.bsky.social
A neat section of the seaside cliffs at my home town. Newfoundland, Canada.
#rocks #cliffs #geology #art
December 3, 2024 at 12:44 PM
Reposted by Jeff
borealman63.bsky.social
One of my favourite things to do when I’m exploring the boreal is to examine the different geological features on the Canadian shield. The rocks are fascinating. I like looking at glacial erratics which have been transported here from elsewhere. #geomorphology #geology #nature #canada #rocks
Glacial erratic on a beach at Whitefish Bay, Lake of the Woods in Ontario, Canada. Creeping Charlie vine on a rock outcrop at Kenora, Ontario. Large inclusions in this boulder, another glacial erratic! Rock cliff face with some kind of layered rocks - ancient sedimentary rocks maybe?
December 4, 2024 at 4:08 AM
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shutterbuglg.bsky.social
Always wanted to visit the Black Canyon of the Gunnison National Park. The painted wall didn’t not disappoint! #blackcanyonofthegunnison #nationalparks #colorado #paintedwall #photography #blackcanyon #Gunnison #landscapephotography
November 22, 2024 at 3:26 AM
Reposted by Jeff
campfirecreations.bsky.social
📍Zion National Park, Utah ⛰️
Snow covered mountains in one of my favorite parks.🔥
#travel #explore #photography #zion #nationalparks #utah

📸 Alex Moliski
November 24, 2024 at 11:14 PM
Reposted by Jeff
ibraumo.bsky.social
#brycecanyon #nationalparks #nature #photography
November 26, 2024 at 1:56 AM