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.
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
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.
When dug up, it's creamy white, but "brightens" to violet in sunlight, then fades to off-white when left in the dark again.
Gorgeous new crystals today!
Spellfiregifts.com 12PM EST
Spellfiregifts.com 12PM EST
February 27, 2026 at 12:49 PM
Gorgeous new crystals today!
Spellfiregifts.com 12PM EST
Spellfiregifts.com 12PM EST
Hackmanite
Lake Erie (Ohio)
Self-collected
LW UV🔦
#rockhound #fluorescentmineral #explore #geology #glow
Lake Erie (Ohio)
Self-collected
LW UV🔦
#rockhound #fluorescentmineral #explore #geology #glow
December 14, 2024 at 6:08 PM
Hackmanite
Lake Erie (Ohio)
Self-collected
LW UV🔦
#rockhound #fluorescentmineral #explore #geology #glow
Lake Erie (Ohio)
Self-collected
LW UV🔦
#rockhound #fluorescentmineral #explore #geology #glow
5.24-carat hackmanite, a variety of sodalite exhibiting tenebrescence, the ability of minerals to change color when exposed to light.
Original post
Original post
July 20, 2026 at 3:20 PM
5.24-carat hackmanite, a variety of sodalite exhibiting tenebrescence, the ability of minerals to change color when exposed to light.
Original post
Original post
This Hackmanite Octo piece is the star of the show this week.
Very large full UV purple and orange
Coming tomorrow on www.spellfiregifts.com 12PM EST
Very large full UV purple and orange
Coming tomorrow on www.spellfiregifts.com 12PM EST
June 12, 2025 at 5:23 PM
This Hackmanite Octo piece is the star of the show this week.
Very large full UV purple and orange
Coming tomorrow on www.spellfiregifts.com 12PM EST
Very large full UV purple and orange
Coming tomorrow on www.spellfiregifts.com 12PM EST
Got a big hunk of hackmanite, check out this -*✨T e n e b r e s c e n c e ✨*- the purple will fade over the next couple hours in sunlight, faster if I shine a bright light on it
August 5, 2025 at 6:58 PM
Got a big hunk of hackmanite, check out this -*✨T e n e b r e s c e n c e ✨*- the purple will fade over the next couple hours in sunlight, faster if I shine a bright light on it
5.24-carat hackmanite, a variety of sodalite exhibiting tenebrescence, the ability of minerals to change color when exposed to light.
Original post
Original post
May 19, 2026 at 8:31 AM
5.24-carat hackmanite, a variety of sodalite exhibiting tenebrescence, the ability of minerals to change color when exposed to light.
Original post
Original post
Ack missed my alt text. Here are the pics again
June 12, 2025 at 5:27 PM
Ack missed my alt text. Here are the pics again
holy fuck have you guys heard of hackmanite? new favorite mercury stone
February 9, 2025 at 9:47 PM
holy fuck have you guys heard of hackmanite? new favorite mercury stone
Ok after a few days they faded back so I can show you the direct before shortwave UV/after. This stone is called hackmanite. It’s a kind of sodalite. It will fade back again in a few days.
July 14, 2025 at 8:13 PM
Ok after a few days they faded back so I can show you the direct before shortwave UV/after. This stone is called hackmanite. It’s a kind of sodalite. It will fade back again in a few days.
proposals for gemstones to replace teeth: hackmanite, darkening to near-black in sunlight; ulexite, optically projecting the gum behind it; opal, cracking from temperature shifts like espresso-then-ice
May 4, 2026 at 3:56 AM
proposals for gemstones to replace teeth: hackmanite, darkening to near-black in sunlight; ulexite, optically projecting the gum behind it; opal, cracking from temperature shifts like espresso-then-ice
June 23, 2025 at 1:15 AM
Colour that comes and goes.
#Hackmanite is a variety of #sodalite known for tenebrescence — the ability to change colour when exposed to UV light and slowly fade back. A fascinating example of how #crystal structure can interact with light in dynamic ways.
#UVLight #Rockhound #Minerals #Gemstones
#Hackmanite is a variety of #sodalite known for tenebrescence — the ability to change colour when exposed to UV light and slowly fade back. A fascinating example of how #crystal structure can interact with light in dynamic ways.
#UVLight #Rockhound #Minerals #Gemstones
May 1, 2026 at 4:20 PM
Colour that comes and goes.
#Hackmanite is a variety of #sodalite known for tenebrescence — the ability to change colour when exposed to UV light and slowly fade back. A fascinating example of how #crystal structure can interact with light in dynamic ways.
#UVLight #Rockhound #Minerals #Gemstones
#Hackmanite is a variety of #sodalite known for tenebrescence — the ability to change colour when exposed to UV light and slowly fade back. A fascinating example of how #crystal structure can interact with light in dynamic ways.
#UVLight #Rockhound #Minerals #Gemstones
I randomly discovered this so now is everyone else's sproblem because i'll start do some of these >:3 starting from Hackmanite!
Btw, why did nobody tell me that hackmanite is a mineral that exist and is the coolest??? #gemuary #gemuary26 #hackmanite #landofthelustrous #housekinokuni #lotl #hnk #oc
Btw, why did nobody tell me that hackmanite is a mineral that exist and is the coolest??? #gemuary #gemuary26 #hackmanite #landofthelustrous #housekinokuni #lotl #hnk #oc
January 2, 2026 at 8:04 PM
I randomly discovered this so now is everyone else's sproblem because i'll start do some of these >:3 starting from Hackmanite!
Btw, why did nobody tell me that hackmanite is a mineral that exist and is the coolest??? #gemuary #gemuary26 #hackmanite #landofthelustrous #housekinokuni #lotl #hnk #oc
Btw, why did nobody tell me that hackmanite is a mineral that exist and is the coolest??? #gemuary #gemuary26 #hackmanite #landofthelustrous #housekinokuni #lotl #hnk #oc
If you like cool rocks I suggest you follow me, I am always buying cool rocks and posting the cool rocks I buy
August 11, 2025 at 2:00 AM
If you like cool rocks I suggest you follow me, I am always buying cool rocks and posting the cool rocks I buy
The answer is sodalite and these are the variety hackmanite!! This variety will temporarily change colour when exposed to light, called tenebrescence. ⚒️🧪
Time for another #GuessTheGem!! What mineral do you think these gems are? Hint: this variety of a typically blue mineral changes colour with exposure to light. ⚒️🧪
February 21, 2024 at 12:11 PM
The answer is sodalite and these are the variety hackmanite!! This variety will temporarily change colour when exposed to light, called tenebrescence. ⚒️🧪
Partially terminated Hackmanite crystal. Minor color change, but very fluorescent and phosphorescent
May 24, 2026 at 8:22 PM
Partially terminated Hackmanite crystal. Minor color change, but very fluorescent and phosphorescent
May 9, 2025 at 2:34 AM
Arkansas Sodalite Sundae🍨
with Hackmanite| LW UV🔦
Self-collected and curated
(Origin story in ALT description)
The Sundae included 7lbs+ Sodalite inside of a 4lbs Depression glass, punch bowl.
This was one of my favorite displays to make! #rockhound #fluorescentmineral #nature #explore #glow
with Hackmanite| LW UV🔦
Self-collected and curated
(Origin story in ALT description)
The Sundae included 7lbs+ Sodalite inside of a 4lbs Depression glass, punch bowl.
This was one of my favorite displays to make! #rockhound #fluorescentmineral #nature #explore #glow
December 8, 2024 at 6:40 PM
Arkansas Sodalite Sundae🍨
with Hackmanite| LW UV🔦
Self-collected and curated
(Origin story in ALT description)
The Sundae included 7lbs+ Sodalite inside of a 4lbs Depression glass, punch bowl.
This was one of my favorite displays to make! #rockhound #fluorescentmineral #nature #explore #glow
with Hackmanite| LW UV🔦
Self-collected and curated
(Origin story in ALT description)
The Sundae included 7lbs+ Sodalite inside of a 4lbs Depression glass, punch bowl.
This was one of my favorite displays to make! #rockhound #fluorescentmineral #nature #explore #glow
131 of #365Minerals 🧪⚒️
Sodalite:
- A tectosilicate mineral
- Some specimens fluoresce under UV light
- Forms in plutonic igneous rocks
- Also known as poor man's lapis since it's sometimes used as a cheaper alternative
- Named after its high sodium content #minerals
Sodalite:
- A tectosilicate mineral
- Some specimens fluoresce under UV light
- Forms in plutonic igneous rocks
- Also known as poor man's lapis since it's sometimes used as a cheaper alternative
- Named after its high sodium content #minerals
May 11, 2025 at 11:44 AM
131 of #365Minerals 🧪⚒️
Sodalite:
- A tectosilicate mineral
- Some specimens fluoresce under UV light
- Forms in plutonic igneous rocks
- Also known as poor man's lapis since it's sometimes used as a cheaper alternative
- Named after its high sodium content #minerals
Sodalite:
- A tectosilicate mineral
- Some specimens fluoresce under UV light
- Forms in plutonic igneous rocks
- Also known as poor man's lapis since it's sometimes used as a cheaper alternative
- Named after its high sodium content #minerals
Love Lake Erie rocks!
December 10, 2024 at 6:19 AM
Love Lake Erie rocks!
Today's ROTD ⚒️ 🧪 is Hackmanite! A light pink to pale violet variety of sodalite. Its an unusual gem because it exhibits an optical property known as "tenebrescence," a type of reversible photochromism. This feature allows it to temp change color when exposed to different light forms. (Especially UV)
October 25, 2023 at 3:17 AM
Today's ROTD ⚒️ 🧪 is Hackmanite! A light pink to pale violet variety of sodalite. Its an unusual gem because it exhibits an optical property known as "tenebrescence," a type of reversible photochromism. This feature allows it to temp change color when exposed to different light forms. (Especially UV)