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DL Whitney

@sorosilicate.bsky.social
107 followers 116 following 35 posts

Metamorphic petrologist who also does some tectonics and teaches mineralogy. I love rocks and minerals and field work. Also reading, art, and cats.

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DL Whitney @sorosilicate.bsky.social · 20/09/2026
Subducted chert with perfect little #garnets scattered in a sea of #quartz, as seen under cross polarized and plane polarized light; FOV ~ 1.5 mm. Laytonville, California US. Garnet has previously won #MineralCup and maybe 2026 is finally the year for #quartz! #MinCup26
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Reposted by DL Whitney
Vicky Veritas @vickyveritas.bsky.social · 19/09/2026
A small but beautiful gem quality golden terminated #andalusite that deserves your vote. Today I am voting for a mineral that didn’t get eliminated (unlike yesterday, DOH!) Progress 😆 #MinCup26 ⚒️ sci-fi 🧪 🖖🏼 scifi Geosciences #WomenInSTEM geology #geosky #GIS 🍎 🪐 🔭 🌋 📚 🌿
Golden terminated gem quality #andalusite. From Mindat: https://www.mindat.org/photo-711070.html
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Reposted by DL Whitney
Ele Willoughby @minouette.bsky.social · 19/09/2026
Andalusite gets arts points as gem & physics points for pleochroism & as index mineral. But Cuprite wins art vote as a red pigment in glass, enamels, bronze patinas & ceramics. Colours range from blood red to purple/brown in a reducing atmosphere & change to green in an oxidizing kiln. #MinCup26
An oval cut honey brown Andalusite gem via gemstones.com Vase

Hugh Cornwall Robertson
Chelsea Keramic Art Works, Chelsea, Massachusetts, United States
Stoneware; Oxblood glaze
Museum of Fine Arts, Boston: Gift of Edward W. Hooper
for more information see: MFA Online Collections Database

Via cameo.mfa.org

Glaze colour with CupriteTitle: Ritual Tripod Cauldron with Cover (Ding)
Period: Eastern Zhou (770–256 BCE) to Western Han dynasty (206 BCE–9 CE)
Date: 3rd–2nd century BCE
Culture: China
Medium: Bronze [red patina due to Cuprite]
Dimensions: H. 7 7/8 in. (20 cm); Diam. 8 3/4 in. (22.2 cm)
Classification: Metalwork
Credit Line: John Stewart Kennedy Fund, 1913
Object Number: 13.220.41a, b
Curatorial Department: Asian Art

Via The MetTitle: Portrait medal of Jacques Boyceau (obverse); Allegory of the Cycle of Life (reverse)
Artist: Abraham Dupré (1604–1647) , Paris
Date: model, 1624 (contemporary cast)
Culture: French
Medium: Bronze (copper alloy with reddish brown cuprite patina)
Dimensions: Diam. 7.2 cm, wt. 81.31 g.
Classification: Medals
Credit Line: Robert Lehman Collection, 1975
Object Number: 1975.1.1321
Curatorial Department: The Robert Lehman Collection

Via The Met 

Medal shows balding bearded man profile in Renaissance garb with big ruff, in bad relief.
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DL Whitney @sorosilicate.bsky.social · 19/09/2026
One day during field work in Türkiye, I sat in a dry stream bed to eat lunch and found this #andalusite + quartz rock next to my foot! I walked upstream until I found the outcrops, and ended up with an unexpected new research project on this surprising rock! #MinCup26 #MineralCup
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DL Whitney @sorosilicate.bsky.social · 19/09/2026
If you (or the Earth) heats up #kyanite at low pressure (shallow depths), you get #andalusite! Both are Al2SiO5, but with distinct crystal structures. #MinCup26 #MineralCup
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Reposted by DL Whitney
Vicky Veritas @vickyveritas.bsky.social · 19/09/2026
“In thin section (a slice of rock about 30 µm or 0.03 mm thick) (andalusite) chiastolite makes beautiful images. The textbook-quality photo above is by Chris Gammons of a specimen collected by Joel Dietrich in the Flint Creek Range of southwest Montana” From @richardgibson.substack.com Link in ALT!
Andalusite chiastolite showing strong crosses with perfect symmetry in thin section. More at: https://richardigibson.substack.com/p/andalusite
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DL Whitney @sorosilicate.bsky.social · 19/09/2026
Beautiful #andlausite with a crystallographically-controlled cross of #graphite inclusions (chiastolite). It would be epic to have an andalusite vs graphite match, if only andalusite can prevail over cuprite. #MinCup26 #MineralCup
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DL Whitney @sorosilicate.bsky.social · 16/09/2026
The dark mineral in these plane (L) and crossed polarized (R) light photos of a subducted metasediment from Corsica is mostly #graphite. Some occurs as inclusions in #lawsonite, defining micro-folds. #MinCup26, #MineralCup
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DL Whitney @sorosilicate.bsky.social · 14/09/2026
#Riebeckite occurs in some alkali granites and banded iron formations and it can occur in blueschist. It is more iron-rich (including Fe3+) than the more famous #glaucophane. This photo shows a sodic amphibole zoned from Mg-rich core to iron-rich rim in chert that was subducted. FOV 2 mm. #mincup26
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DL Whitney @sorosilicate.bsky.social · 07/09/2026
Pink #andalusite intergrown with blue #kyanite — which came first? #Mincup26 #mineralcup
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DL Whitney @sorosilicate.bsky.social · 10/08/2026
www.facebook.com/share/19JV7s...
facebook.com
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DL Whitney @sorosilicate.bsky.social · 18/06/2026
Source: Frontiers for Young Minds
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DL Whitney @sorosilicate.bsky.social · 08/03/2026
International Women’s Day march in Berlin
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DL Whitney @sorosilicate.bsky.social · 01/10/2025
Epic #kyanite crystals reveal their colors when split open. We are tracking variation in extent of kyanite to sillimanite transformation in a metamorphic dome — it varies from 0-100% with structural location in the dome: one of the many geo-useful and fun things you can do with kyanite. #MinCup25
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DL Whitney @sorosilicate.bsky.social · 01/10/2025
These white #kyanite crystals in a biotite-gedrite schist from central Australia somehow missed out on the titanium, iron, and other trace elements that kyanite typically contains to give it the iconic blue and other colors. #MinCup25
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DL Whitney @sorosilicate.bsky.social · 01/10/2025
This rock in western Norway originated as basalt in an ancient ocean, then it was buried (subducted) tens of kilometers and heated over 800 C to create this beautiful #kyanite. The alignment of the kyanite indicates deformation. #MinCup25
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DL Whitney @sorosilicate.bsky.social · 01/10/2025
Chromium-rich #kyanite blood, as seen with cathodoluminescence imaging. #MinCup25
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DL Whitney @sorosilicate.bsky.social · 01/10/2025
#kyanite party (Roan, Norway) #MinCup25
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DL Whitney @sorosilicate.bsky.social · 01/10/2025
I’m very excited that #tugtupite made it to the finals but can it do this? Folded #kyanite in a high-pressure quartzite, western Türkiye. #MinCup25
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DL Whitney @sorosilicate.bsky.social · 29/09/2025
Hematite is red, #kyanite is blue, And also green, white, black, and orange too #MinCup25
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DL Whitney @sorosilicate.bsky.social · 29/09/2025
#kyanite (blue) replacing or being replaced by pink #andalusite. Bonus: there is also #sillimanite, so this a rare locality containing 3 Al2SiO5 minerals (polymorphs). Lesjaverk, Norway. #MinCup25
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DL Whitney @sorosilicate.bsky.social · 29/09/2025
#kyanite wave (Western Gneiss Region, Norway) #MinCup25
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Reposted by DL Whitney
Mineralogical Society of America @mineralsocamerica.bsky.social · 25/09/2025
NOTE: MSA Inaugural Annual Meeting: Feb, 16-18, 2026, Tucson, AZ, USA This will follow the Tucson Gem and Mineral Show. On Feb. 17 and 18 there will be a series of talks and poster sessions. Abstracts due: Oct. 31. Registration will be through the MSA website at www.msaweb.org
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DL Whitney @sorosilicate.bsky.social · 23/09/2025
#kyanite fields forever, or until the next orogeny #MinCup25
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DL Whitney @sorosilicate.bsky.social · 23/09/2025
#kyanite in biotite gneiss from the Entia Dome, central Australia. Kyanite forms deep in the crust before it makes its way to the Earth’s surface, a slow and much more challenging journey than taenite’s fall through space. #MinCup25
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DL Whitney @sorosilicate.bsky.social · 13/09/2025
#kyanite volcano (not really a thing but a nice way to display the different colors of kyanite) #MinCup25
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DL Whitney @sorosilicate.bsky.social · 11/09/2025
#Garnet swimming in a sea of #Titanite in a Franciscan Complex metamorphic rock, as seen in plane and cross polarized light. Photo by Sarah Brandt. #MinCup25
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DL Whitney @sorosilicate.bsky.social · 11/09/2025
#Titanite from the Franciscan subduction complex, California, as seen under plane and cross polarized light in a petrographic microscope. Field of view about 2 mm. Photo by Sarah Brandt. #MinCup25
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DL Whitney @sorosilicate.bsky.social · 05/08/2025
Magnetic and Crystallographic Fabric Analyses of Amphibolite: A Proposed Methodology Applied to a Migmatite Dome - Hamelin - 2025 - Journal of Geophysical Research: Solid Earth - Wiley Online Library agupubs.onlinelibrary.wiley.com/doi/10.1029/...
agupubs.onlinelibrary.wiley.com
Magnetic and Crystallographic Fabric Analyses of Amphibolite: A Proposed Methodology Applied to a Migmatite Dome
Anisotropy of Magnetic Susceptibility provides an efficient, first-order characterization of amphibole-dominated rock fabrics Rapid, simple methods open applications to structural field studies i...
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DL Whitney @sorosilicate.bsky.social · 28/09/2024
#kyanite is beautiful at all scales, #MinCup24
Kyanite in a matrix of quartz under crossed polarized lightKyanite in a matrix of quartz under plane polarized light
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DL Whitney @sorosilicate.bsky.social · 19/09/2024
Pink #corundum with green #clinopyroxene in thin section (plane light, 2 mm FOV), Berit metaophiolite, Türkiye, #MinCup24
Pink corundum, green cpx
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DL Whitney @sorosilicate.bsky.social · 19/09/2024
#corundum in a petrographic thin section (plane light), with green #clinopyroxene, field of view ~2 mm, Doğanşehir, Türkiye, #MinCup24
Pink corundum with green cpx
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DL Whitney @sorosilicate.bsky.social · 13/09/2024
#Titanite from gneiss from Finnøya, Norway, as seen in thin section. Clear, rounded inclusions are apatite. Field of view ~0.5 mm. #MinCup24
Diamond shaped titanite, plane lightDiamond-shaped titanite, crossed polars
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DL Whitney @sorosilicate.bsky.social · 12/09/2024
#Kyanite in blue, green, white, and black. #MinCup24
Different colors of kyanite
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DL Whitney @sorosilicate.bsky.social · 11/09/2024
A heap of #quartz. Go ahead and try this with mercury. #MinCup24
Quartz
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DL Whitney @sorosilicate.bsky.social · 11/09/2024
#omphacite #MinCup24
EclogiteEclogite
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