#Tenebrescent
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pfsmet.bsky.social
And here is the updated color summary for #MinCup25!
Colorless (white-grey-black) minerals were quickly kicked out, unfortunately. Maybe next time, there can be a max color level for participation? Tenebrescent #tugtupite can participate again and take a glorious win after exposure to UV ;-)
Bracket of MinCup25. For each mineral, the typical appearance is shown with a small image. Of course, some minerals have multiple colours, so snippets from the images on the voting posts or the website were taken. Colored lines connect the different rounds.
October 2, 2025 at 9:15 AM
bike4evr.myatproto.social
Easy peasy.
Called reindeer blood in some circles, is found in Inuit stories, is tenebrescent, fluorescent, phosphorescent, and piezoelectric … #tugtupite yes please!
mineralcup.bsky.social Mineral Cup & Ore Cup @mineralcup.bsky.social · Oct 1
#MinCup25 Final: After a month of learning and laughter, we’re at the final match to determine the 2025 Mineral Cup Champion! We have blue blades of #kyanite up against optical magician #tugtupite.

Vote: www.mineralcup.org/2025/vote/r5...
Results: www.mineralcup.org/2025/results...
Vote in 2025 Final Match — Mineral Cup
Click here to vote in Kyanite vs Tugtupite Photo credits: John Sobolewski and Parent Géry
www.mineralcup.org
October 1, 2025 at 4:31 PM
minouette.bsky.social
While blue kyanite is used in jewelry, porcelain & pottery glazes, plus gets physics points as an index mineral, it’s the extraordinary ‘reindeer blood’ tenebrescent, & phosphorescent tugtupite “King of Fluorescent Minerals” which is also a gem, gaining both art and physics points for me. #MinCup25
Kyanite is a naturally occurring aluminum silicate mineral that typically forms as bladed crystals, and occasionally it occurs as radiating masses of crystals. The name kyanite is derived from the Greek word kyanos which means “blue.” Gem quality kyanite has a royal blue color similar to fine sapphire. This material is highly prized by those who cut gemstones. Kyanite can be cut en cabochon, faceted, or fashioned into beads, however its variability in hardness and color zoning can make it difficult to fashion and facet. Transparent intense blue kyanite is beautiful and is considered to be an exotic gemstone because it is not often seen in jewelry. Kyanite is predominately found in shades of blue and green, but it can also be yellow, white and orange. This 5.87ct gem is an intense deep blue color and the largest and finest kyanite from Nepal in the National Gem Collection. Smithsonian Museum" The Smithsonian acquired two “ulu” silver pendants with tugtupite cabochons (ulu is an all-purpose knife traditionally used by Inuit, Yupik, and Aleut women), designed and created by Mike Møller. These are the first tugtupite gems acquired for the National Gem Collection. https://naturalhistory.si.edu/object/nmnhmineralsciences_14272125?geogallery=Tugtupite&node=14624I’m Tugtupite 6.00 ct Oval Cut 15.10 x 9.50 x 6.50 mm The same oval cabuchon is shown under regular light as white and blood red and under UV as scarlet and burgundy, against a black background. Via https://gemologicalcollections.com/product/tugtupite-6-00-ct-oval-cut-15-10-x-9-50-x-6-50-mm-greenland-w399/ Gorgeous cut blood red tugpite gem from Greenland in the Smithsonian mineral collection
October 1, 2025 at 12:45 PM
saavikford.bsky.social
Last semifinal! It’s #Tugtupite for me! It’s got an Indigenous name for reindeer blood & as elsewhere, it’s:

tenebrescent, fluorescent in short & long wave UV & phosphorescent—from Greenland, it would go dim & mild during the long winters and then bright and intense during summer(!)

#MinCup25
September 30, 2025 at 12:18 AM
minouette.bsky.social
A tough call for #MinCup25 but I think I have to give dioptase the arts vote as a pigment since ancient times (i.e. on Neolithic sculpture, Asian murals & Russian icons), though ‘reindeer blood’ tenebrescent, & phosphorescent, tugtupite “King of Fluorescent Minerals” is also a gem.
Frontal closeup view of Neolithic sculpture of a human figure face in lime plaster with eyes highlighted in Dioptase from Ain Ghazal , Jordan, from the Musée du Louvre, Paris, via Wikipedia An apsara [Buddhist religious figure] painted on the ceiling of Cave 1 of the ancient Chinese Kizil caves. Greens are mainly dioptase via The Glorious Kizil Grottoes By staff reporter YU XIANGJUN, 2015-September-28, China Today Our Lady of Life-Giving Spring Svetlana Fatyanova•Russia Original artwork, 32×40 cm, 2024 employs dioptase as a pigment. This Russian religious icon depicts Madonna and Child with angels on either side, seated on a fountain with water flowing in three spouts to the people, in three groups of four, below. They are catching the water and helping one seated and one reclined figure to drink. The figures are dressed in red and blue and pink and the background is guilt in gold foil. The Smithsonian acquired two “ulu” silver pendants with tugtupite cabochons (ulu is an all-purpose knife traditionally used by Inuit, Yupik, and Aleut women), designed and created by Mike Møller. These are the first tugtupite gems acquired for the National Gem Collection. https://naturalhistory.si.edu/object/nmnhmineralsciences_14272125?geogallery=Tugtupite&node=14624
September 30, 2025 at 12:51 PM
gsa-mgpv-division.bsky.social
#MinCup25 Quarterfinal 2 - ☀️ #Perovskite vs 🌸 #Tugtupite. A mineral empowering solar cells (and found in the rain in brown dwarf stars!) faces the vivid pink tenebrescent, fluorescent, and phosphorescent feldspathoid.

#minerals #mineralogy
September 26, 2025 at 2:39 PM
minouette.bsky.social
I’ll grant that it’s cool that “Borg cube” perovskite could be formed in a Brown Dwarf but I’m voting for reindeer blood tugtupite “King of Fluorescent Minerals,” which is tenebrescent (changes colour in UV) & phosphorescent so gains my physics vote plus it’s also a gem on the arts front #MinCup25
This is a metallic silver cubic Perovskite sample on a green background. It really does resemble the Borg cube from Star Trek. Via https://www.mindat.org/photo-214655.html The Smithsonian acquired two “ulu” silver pendants with tugtupite cabochons (ulu is an all-purpose knife traditionally used by Inuit, Yupik, and Aleut women), designed and created by Mike Møller. These are the first tugtupite gems acquired for the National Gem Collection. https://naturalhistory.si.edu/object/nmnhmineralsciences_14272125?geogallery=Tugtupite&node=14624 Tugtupite 6.00 ct Oval Cut 15.10 x 9.50 x 6.50 mm The same oval cabuchon is shown under regular light as white and blood red and under UV as scarlet and burgundy, against a black background. Via https://gemologicalcollections.com/product/tugtupite-6-00-ct-oval-cut-15-10-x-9-50-x-6-50-mm-greenland-w399/
September 26, 2025 at 12:33 PM
saavikford.bsky.social
As in Rounds 1&2, it’s #Tugtupite for me! It’s got an Indigenous name & as @redsage.bsky.social said it is:

tenebrescent, fluorescent in short & long wave UV & phosphorescent—from Greenland, it would go dim & mild during the long winters and then bright and intense during summer(!)

#MinCup25
September 26, 2025 at 1:05 AM
blastylavagrrrl.bsky.social
#Tugtupite is...
#Tenebrescent -It darkens when exposed to UV.
#Fluorescent -It fluoresces under long-, mid-, or shortwave UV.
#Phosphorescent -It GLOWS IN THE DARK!!!!

www.flickr.com/photos/28617...
www.flickr.com/photos/28617...
www.flickr.com/photos/28617...

#MinCup25
Two photos of the same rock. The top photo shows a dirty white and pink stone. The pink is a soft baby pink. The lower photo is the same rock after it has been exposed to UV light. The light pink areas are noticeably darker. This darkening of the mineral after UV exposure is called tenebrescence. Two photos of the same rock. The top photo shows what happens when the rock is exposed to shortwave ultraviolet light: An extremely bright neon pink emerges where the mineral tugtupite is found. The lower photo has the formerly pink tugtupite a hot yellow/orange shade under longwave ultraviolet light. This changing of the mineral's color upon different lengths of UV exposure is called fluorescence. Two photos of the same rock. The top photo shows what happens when the rock is exposed to shortwave ultraviolet light: An extremely bright neon pink emerges where the mineral tugtupite is found. The lower photo displays the formerly pink areas glowing furiously. The darkest pink from the UV image is now a pale pink, while the lightest areas are almost a bluish-white color. The glow following exposure of tugtupite to UV light, after all light has been removed, is called phosphorescence.
September 26, 2025 at 1:21 AM
saavikford.bsky.social
As in Round 1, it’s #Tugtupite for me! It’s got an Indigenous name & as @redsage.bsky.social said it is:

tenebrescent, fluorescent in short & long wave UV & phosphorescent—from Greenland, it would go dim & mild during the long winters and then bright and intense during summer(!)

#MinCup25
September 20, 2025 at 12:13 PM
minouette.bsky.social
The very rare hydrocarbon mineral carparthite (exceptionally pure coronene C24H12) is fluorescent but tugtupite is called “King of Fluorescent Minerals,” plus it’s tenebrescent (changes colour in UV) & phosphorescent so gains my physics vote plus it’s also a gem on the arts front #MinCup25 #scicomm
Two images of carpathite under regular light and UV to show its fluorescence via mindat.org. Under regular light the rock looks grey and rust with some visible white and lime thin linear crystals, while under UV the crystals glow an intense blue. The Smithsonian acquired two “ulu” silver pendants with tugtupite cabochons (ulu is an all-purpose knife traditionally used by Inuit, Yupik, and Aleut women), designed and created by Mike Møller. These are the first tugtupite gems acquired for the National Gem Collection. https://naturalhistory.si.edu/object/nmnhmineralsciences_14272125?geogallery=Tugtupite&node=14624 Tugtupite 6.00 ct Oval Cut 15.10 x 9.50 x 6.50 mm The same oval cabuchon is shown under regular light as white and blood red and under UV as scarlet and burgundy, against a black background. Via https://gemologicalcollections.com/product/tugtupite-6-00-ct-oval-cut-15-10-x-9-50-x-6-50-mm-greenland-w399/
September 20, 2025 at 1:03 PM
mineralmatters.bsky.social
Mineral Matters # 505 - Tenebrescent Zircon
#mineralmatters #minerals
open.substack.com/pub/mineralm...
Tenebrescent Zircon
Mineral Matters #505
open.substack.com
November 5, 2024 at 11:13 PM
feralharp.bsky.social
Oh dear. What you’ve written fits all too readily into the song “Plastic Jesus.”

Tenebrescent & fluorescent
In UV, and phosphorescent,
A Greenlander that changes with the times.
Bright in summer, dim in winter,
It needs your vote to be a winner.
Tugtupite’s a name to know and love!
September 8, 2025 at 12:58 PM
chrissysparksart.bsky.social
I found out what the rocks are! Tenebrescent Scapolite: Scapolite variety of Hackmenite from Greenland.
January 24, 2025 at 1:40 PM
mewgle.bsky.social
Says right there
Her fur is tenebrescent, it changes colour when exposed to uv light
May 4, 2025 at 6:41 PM
chrissysparksart.bsky.social
I found out what the rocks are! Tenebrescent Scapolite: Scapolite variety of Hackmenite from Greenland.
January 24, 2025 at 1:41 PM
redsage.bsky.social
Ok everyone, we are down to the last ~45 minutes on this and it's really close. Vote for the tenebrescent reindeer blood from the land of snow! Vote tugtupite!! I can't believe I'm saying this, and this endorsement is for Mineral Cup only, but BLOOD BEFORE BORG!
September 26, 2025 at 11:13 PM
elysiamacht.bsky.social
Pie-zo-pizza rock #Tugtupite is the fave mineral of #pugs, Ninja Turtles & #DeanWinchester, so we make all sad if we don't vote for the beryllium aluminium tectosilicate #gemstone

More info in ALT! Photos behind link
www.minershop.com/products/tug...

www.elesyngaea.com/listing/1055...

#MinCup25
A pizza slice shaped rock on a palm, parts glowing in UV light. Quoting Elesyn Gaea site: "This FANTASY ROCK contains the super rare TUGTUPITE, sodalite, chkalovite, analcime, a few spots of uranyl ion, and arfvedsonite. This is a very complex and beautiful medium size piece. Tenebrescent. Fantasy Rocks are one of the most sought after fluorescent minerals in the world due to the beautiful and complex combination of colors when exposed to UV lighting. Tugtupite is one of the most sought after gemstones because of its rarity, exclusivity, color, and its tenebrescence; and when it is mixed with other beautiful fluorescent minerals from Greenland, it creates a galaxy-looking combination known as "Fantasy Rock" (term coined by Mark Cole from the wonderful website called "Natures Rainbows"). Fantasy Rocks is a term that only refers to the fluorescent mineral combinations (of at least 3-4 or more glowing color combinations) that only come from the Ilimaussaq Complex in Greenland." Tugtupite under midwave light, looking lilac-y violet purple with bluer areas. From the Minershop. com site with many more amazing tugtupite photos. The light effects are fantastic. Smithsonian says: A variety of fascinating optical properties, including tenebrescence, fluorescence, and phosphorescence. Tenebrescence is the ability of minerals to change or darken in color when exposed to light. Tugtupite is strongly tenebrescent with colors changing from white or light pink, to vivid red and even purple-red. The color changes quickly, within minutes, when exposed to sunlight or short-wave ultraviolet light. Absence of daylight during the long arctic winter causes tugtupite to naturally lose its color over weeks to months, returning to white or very light pink. This color-change is reversible, as tugtupite will again regain its red color when re-exposed to sunlight. Tugtupite is also strongly fluorescent in both shortwave (SWUV) and long-wave (LWUV) ultraviolet light. Under SWUV light, it glows strongly orange to orangey-red; whereas under LWUV light, it glows weakly salmon-pink. It is sometimes referred to as the “King of Fluorescent Minerals.” Tugtupite is also phosphorescent, with the color fading from a light to dark-green after a few minutes once an UV light source has been extinguished. A round, cut tugtupite gemstone from the Smithsonian national museum. Info from there continues: Tugtupite was first discovered in 1957, at Tugtup agtakôrfia, Greenland, a few kilometers to the east of the town of Narssaq, by Professor Henning Sørensen. The name tugtupite is derived from the locality where the mineral was first found. Tugtupite is also referred to as Tuktu, a named derived from the Greenlandic Inuit word for reindeer (tuttu) and means “reindeer blood.” Tugtupite is a rare silicate, closely related to sodalite. The red variety of the mineral tugtupite has been used as a gemstone since 1965. It is typically massive in nature, however, small prismatic crystals that are transparent have been found growing on cavity walls in massive tugtupite. "EAT PIE, KILL DEMONS" for our pie-zo-electric vote of choice. A very handsome actor, Jensen Ackles, as Dean Winchester wearing a suit + bow tie on the left, standing next to a neon sign that has a pie slice at the top over "EAT PIE" text in blue like it, above "KILL DEMONS" in red. Dean's white shirt colours reindeer blood on the snow from the neon lights, in honour of supernatural tugtupite. Be like Dean, vote for blood. It's originally a post from someone thanking everyone celebrating 300 episodes, saying "It's like the Dean Winchester bat signal, but neon". Dean Winchester will come after you if you don't vote for his favourite rock, tugtupite. It's #Supernatural endorsed blood rock voting time! Also me thanking for anyone voting for it through this.
September 26, 2025 at 9:29 PM
northgirlrocks.bsky.social
Whoa, I'd never heard of tenebrescent before!! That's so cool! It's pretty too 🩷
January 16, 2025 at 11:33 PM
redsage.bsky.social
I’m lobbying for tugtupite. It’s tenebrescent, fluorescent in both short and long wave UV light, and even phosphorescent…! Since it is from Greenland, it would go dim and mild during the long winters and then bright and intense during summer, and I love that.
September 8, 2025 at 3:16 AM
chrissysparksart.bsky.social
Here’s a picture showing this Orion Wood Slice Painting in sunlight and UV light - along with info about the glowing mineral used in Orion’s Belt! #geology #sciart #astroart #space #spaceart
This glowing mineral is Scapolite variety Hackmanite from Greenland. Tenebrescent scapolite is a rare, semi-precious gemstone that temporarily changes color when exposed to UV light.
February 4, 2025 at 1:14 PM
c0nc0rdance.bsky.social
There's another unusual property of a specific type of sodalite called 'hackmanite': it's 'tenebrescent', meaning it changes COLOR in response to UV light.

When dug up, it's creamy white, but "brightens" to violet in sunlight, then fades to off-white when left in the dark again.
Hackmanite: The Gemstone That Changes Colors – Geology In
Hackmanite is a rare variety of sodalite, a mineral belonging to the feldspathoids group. It is known for its unique color-changing prop...
www.geologyin.com
April 14, 2025 at 11:18 PM
minouette.bsky.social
Caesium-rich pollucite is mined for use in oil drilling. Tugtupite’s name comes from Inuit for reindeer blood. It’s vitreous, transparent to translucent, tenebrescent (changes colour in UV). Called the “King of Fluorescent Minerals,” is phosphorescent so gets my physics vote plus a gem. #MinCup25
Oval brilliant-cut pollucite, 9.51 cts, 16.3 x 12.7 mm, Afghanistan. © The Gem Trader The Smithsonian acquired two “ulu” silver pendants with tugtupite cabochons (ulu is an all-purpose knife traditionally used by Inuit, Yupik, and Aleut women), designed and created by Mike Møller. These are the first tugtupite gems acquired for the National Gem Collection. https://naturalhistory.si.edu/object/nmnhmineralsciences_14272125?geogallery=Tugtupite&node=14624 Tugtupite from Kuannersuit Plateau, Greenland © Amy & Michael Biavati Shot in the visible spectrum of light it appears like a white and grey rock with splotches of deep red. https://www.le-comptoir-geologique.com/tugtupite-encyclopedia.html Tugtupite from Kuannersuit Plateau, Greenland © Amy & Michael Biavati The same specimen as the previous photo shot under a black light (UV) shows strong red and green glow. https://www.le-comptoir-geologique.com/tugtupite-encyclopedia.html
September 8, 2025 at 1:25 PM
redsage.bsky.social
Tough matchup - pollucite contains cesium, and I love the time minerals, but tugtupite is hot pink, named for reindeer blood, and tenebrescent (color intensifies with exposure to UV / sunlight), and that’s all cool as hell. Vote team tugtupite! www.naturalhistory.si.edu/explore/coll...
September 8, 2025 at 3:12 AM