Thread by @mikamckinnon

I had exactly 30min entry-to-exit to explore @hmns.

I’d heard they have a solid collection of trilobites & the massive cut blue sapphire Siren of Serendip is a special exhibit.

But with the clock ticking down, I raced up the stairs & tumbled into Cullen Hall of Gems & Minerals.

#Crocoite: Shiny red-orange spiketastic lead chromate.

Despite being named for colour-matching saffron, lead makes it firmly “Do Not Lick.”

This particular spikefren is from Adelaide Mine, Tasmania, sticking with “everything cute in Australia can secretly kill you” theme.

#Fluorite: a honkin’ massive cube of calcium fluorite with that particular dull-waxy translucence I wanna pet so bad.

No UV light to see if it’d fluoresce pretty colours for me.

From Nikolaevskiy Mine in Russia where hot sulfide solutions crystallized in limestone caverns.

#Fluorite is soft & non-deadly, but doesn’t taste like anything in particular.

Considering it’s usually an iconic shape (cube, rarely octa or dodeca) & freaking FLUORESCES so it’s easy ID, lickability is “You could, but why bother?”

#Sulfur (#Sulphur), aka brimstone! Way less scary than you’d expect for a mineral from the pits of Hell.

Sulfur’s resinous-greasy texture & wee knobs of bright yellow are cute. Usually dipyramids, these ones are unusually blocky tabs.

VERY soft. Not stinky unless you hurt them.

More Italian sulfur (hi yellow fren!) & two samples #Selenite

Yeah. That dancing curlyque rams horn AND the “I’m too elegant for your bs” perfect prism are the same thing!

Selenite is a specific variety of #gypsum named for transmitting cool white light like moonshine.

Whoops, forgot prior image description:

Three minerals:
1. a translucent bright yellow parallelogram
2. a milky-white curling tube shooting from a crystalline base and spiraling like a tube worm, and
3. a clear perfectly prismatic crystal emerging from rough matte white rock.

Yarrr #gold! on a base of #quartz. This specific sample is nicknamed “The Dragon” because it’s all fierce & ferocious, which is handy because it can horde itself.

From Colorado Mine in the Sierra Nevadas of California, quartz veins in Jurassic marine rocks & Mesozoic volcanics.

#Pyrite on #quartz, aka foolsgold because it’s shiny & golden, but is actually iron x sulfur.

Compare/contrast pyrite’s precise geometric lines to the wild & jagged curves of the gold dragon. It’s lighter, harder, & if not crystallized can decompose into nasty sulfuric acid goo.

#Wulfenite (matte orange tabs), #Galena (hefty steel grey cube) on #Dolomite, #Pyromorphite (globby fren), & more wulfenite (bright shiny orange party time) & #Mimetite (matte tangerine globs)

No licking. So much no licking with lead eeevvvvvverywhere. Such pretty, much bad idea

#Wulfenite is lead molybdate that‘s usually pretty flame-colours can sometimes be grey, green, brown, black, or colourless because fuck you if you think colour is diagnostic in mineral ID.

But it does usually grow in sharp chiclet-tabs. Although sometimes it’s round or pyramids.

#Mimetite is lead, arsenic, & chlorine with a bit of oxygen tossed in to keep it from being a complete cesspool of toxicity.

It’s usually shiiiiny tiny hexes, although it can occasionally be wee rounded barrels & globs (like this).

#Pyromorphite is lead chlorine phosphate that’s classically waxy green skeletal hexagonal barrels, so... uh, pretty much as not like this as you can get?

Pyromirphite & mimetite are the ends of a continuous series of oxidized lead-chloride sibling-minerals.

#Galena is lead & sulfur. Not stinky unless you drip acid on it, at which point it’s a stink-bomb of rotting eggs.

Heavy. Soft-ish. Cubical (yes, it grew like that; that’s the mineral equivalent of #IWokeUpLikeThis) or rarely octahedral. Lead-grey, metallic but tarnishes dull.

Of this quartet, #galena is a primary lead mineral we’ve been using as ore since 3000BCE while the others are secondary minerals found in the oxidized zones of lead deposits.

In juuuuust the right conditions, #wulfenite can precipitate out of volcanic vent gases. Do not huff.

More “Do Not Lick” lead minerals: #Wulfenite (x2), #Mimetite, and that flowering tulip bouquet is #Cerussite, aka white lead.

Cerussite is lead carbonate, a common weathering product of oxidizing galena, & almost always grows as twins.

You’d think with a nickname like “white lead,” #cerussite would always be white, but if you’ve been following along you know the common theme of mineral ID is “hahahaha nope.” when relying on colour.

It can be clear, white, grey, brown, blue, or green; shiny to pearly to earthy

#Legrandite (yellow daisy) & #amethyst with #quartz x2

I’m not really sure why these frens are sharing a case unless it’s maybe showcasing vibrantly-coloured elongated prismatic crystals?

#Legranite is... uh, hydrated zinc arsenate hydroxide? Shit you don’t want to lick with lots of hydrogen & oxygen mixed in & LOTS of hydrogen bonds.

It’s clear/yellow & grows in splays.

Coolest feature?
Proton transfer tunnels down the crystal axis. Go go quantum teleportation!

#Amethyst is #quartz contaminated with iron to make it purple (ah hah, colour is diagnostic!!! although you can heat it up to turn yellow, but then it’s #citrine).

Quartz is everywhere, looks like everything, & these samples are too pretty for triboluminescence (bang to glow).

Moar #cerussite (yes, x3), all from Namibia.

Notice the pretty rainbow in the bottom right — the mineral is a dispersive prism refracting light by wavelength to split it into a spectrum.

#Dioptase (with calcite), a hydrated copper silicate.

I took so many pix that all turned out “eh” at best, but I love this unpopular cousin of emerald. It’s always great colours (shiny green to blue), streaks green (eee!), has freaking perfect cleavage (breaks pretty)

#Fluorite (light cube) on #Sphalerite (dark mass) from Elmwood Mine, Tennessee.

Sphalerite is from the Greek “treacherous” for masquerading as Galena, but since its zinc x sulfur, producing no lead. It’s typically clear (ahahaha) unless contaminated with lead (aka #Marmatite).

Meta-note: The number of mineral names derived from more polite versions of “Ahhhh fuck you stop tricking me I look like a fool!!!” is not insubstantial.

I mean, we’ve ID’d ~3800 minerals with another +30-50 added & -1-2 discredited per year. It’s a mess.

#Aquamarine (star) & #Muscovite (sidekick)

Aquamarine is blue #Beryl, beryllium aluminum silicate. It’s hard & heavy & while it doesn’t taste like anything more than “bland-neutral” it also isn’t dangerous which is good ‘cause it looks so lickable.

#Muscovite is white #mica, a phyllosilicate (silica in sheet-form) with potassium, aluminum, & hydroxides.

Mica grows in sheets you can peel apart. Historically used as heat-resistant window panes, it’s now popular in makeup (shiny) or in nanotech growth. It’s soft & elastic

This (green) aquamarine looks like an oversized jolly rancher but alas has no flavour. File under: “You could lick it, but why?”

Despite being long, thick, and fuckin’ harder than steel, but hexagonal section & apparent microporosity would make it inappropriate for personal use.

#Pyromorphite, redux, this time from Idaho in a delightfully sickly green fitting for a mineral that likes to grow in contaminated industrial soil.

Meta: of course it’s part of the apatite mineral group whose namesake translates as “to be deceptive.”

#Morganite (pink #beryl) on #Albite (sodium #feldspar) with a dusting of #schorl (black #tourmaline) from Urucum Mine, Brazil.

Texture is deceiving: all of these are HARD & heavy minerals. Although the beryl still looks lickable even though I know it’s flavourless. Woe!

I feel like I should say something nifty about #albite because plagioclase #feldspar chemistry is so important to most of the rocks all around us, but... if it’s not labradorite I’m good leaving it until a #MinCup battle.

#Cavansite is just unreal in how vibrantly shiny blue it is (yes, always if sometimes a smidge greener).

It’s hydrated calcium vanadium silicate (ca-van-si*te, a name that embeds its composition) that grows as tabs-to-nobs. Hydration means it’s soft.

Totally squealed over it.

I’m guessing vanadium makes cavansite a poor mineral to kick as most metals are in the “let’s just not” category while anything that blue cannot be healthy, but... look at it!

Just one quick lick to taste-test? it can be a source of calcium! (...that’s a bad idea.)

🎵From little things, big things grow🎵

See that bit of red wire in the lower right? That’s a bit of scrap forgotten in Naica mine that seeded the growth of this entire spectacular #Selenite crystal.

I like this particular #selenite (moonshine crystal from upthread) because it’s such a bursting jazzhands of #gypsum.

“Trash to treasure! Gonna precipitate some hydrated calcium silicate all over your junk & dazzle up this stye! Stop littering or I’ll wrap ya in crystals.”

Moar #selenite, but big & pointy & a freaking perfect example of #gypsum’s natural crystal shape if nothing is constraining it.

It’s a monoclinic thick tabular crystal. Try to imagine where you’d place axes of symmetry or rotation.

This blobby pearly aqua fren is #Smithsonite, a zinc carbonate.

It can be pretty much any colour (clear, white, grey, brown, yellow green, blue, pink, or purple) but is usually a pastel blob. It sometimes fluoresces, but more importantly, it bubbles if you dump acid on it.

...although it does seem kinda mean to dump acid on anything that blobby.

It’d only take a few drops of dilute hydrochloric acid to get the characteristic bubbling (effervescence) or carbonates, but... look at it!

Poor blobbfren. Don’t worry, safe from acid in your display case

#Wulfenite, redux.

Still lots of lead. Still a terrible idea to lick. But look at those delicate thin chips! Unfair for a mineral to look that much like candy.

#Morganite (pink #beryl), #albite (white sodium #feldspar) & #schorl (black #tourmaline), redux, this time from Minas Gerais in Brazil.

I like how the translucence of the beryl allows a peek at how the other minerals constrained its growth.

Missed image description: 3 angles of the same sample, a translucent pink disk sandwiched in a salt&pepper mass of white&black elongated needle-like crystals.

#Aquamarine (blue #beryl) with #muscovite (white mica), redux, from the Haramosh Mountains in Pakistan.

Notice how often we see duplicates of the same combos of minerals? That’s because they grow under similar conditions. They accessorize each other!

#Emerald on #Dolomite and #Muscovite (white mica)

Emerald is dark green #beryl contaminated with chromium or vanadium. So those gorgeous green beryls I wanted to lick before? Pale emeralds.

Dolomite is calcium magnesium carbonate, so bubbles in acid.

I’ve never heard of #Cuprosklodowskite before, but LOOK AT IT! It’s all fuzzy grass-green needles (shape & colour are diagnostic) I just wanna pet it so badly

It’s a hydrated copper uranium (?!) silicate hydroxide, so, uh, despite being relatively soft & silky don’t lick. Or pet

#Azurite (blue) on #Kaolinite from Flinders Range, Australia

Azurite is derived for the Persian word for blue, and is now the namesake for this exact vibrant colour.

It’s a copper carbonate hydroxide, shiny af, & while it doesn’t bubble like most carbonates it dissolves in acid

#Kaolinite is an understated mineral that I love.

It’s a clay used since at least Sumerians, named by 13th century Yuan (Mongol), formerly described in 1637 China.

Kaolinite forms when feldspar weathers, which means it’s stable at surface conditions (resists more weathering).

#Elbaite (watermelon #tourmaline), #albite (sodium #feldspar), & smoky #quartz ...x2, both from Afghanistan

Smoky quartz gets its brown-grey-black when natural irradiation frees silicon.

All #tourmaline is pleochroic: the colour changes by angle. #Elbaite frequently steps it up with distinct polychrome zonation: stripes of colour either along the crystal or from inside-out.

And when those colours are green-white-red? Mmmm, watermelon tourmaline!

Ready for something spectacular?
#Elbaite, #Albite, & #Quartz, redux, from Pedermeira Mine, Brazil

I cooed.
A total stranger struck up conversation with me about it.
Small children came to gawk.
JUST LOOK AT IT!

Bonus on #tourmaline colours:

Iron-rich is blues, blacks, & browns

Magnesium-rich is yellows, oranges, reds, & browns

Lithium-rich is a freaking free-for-all of any colour at all

#Crocoite, redux

‘cause I will always stop to admire cheerful doom-needles of red lead.

For ID tests I have no desire to run, crocoite dissolves in hydrochloric acid

Rutilated #quartz, aka normal quartz shot through with needles of #rutile (the bits that look like straw).

Rutile is titanium oxide, and one of only five ways that exact mix of TiO2 is found in nature.

#Amazonite on #Albite.

#Amazonite is green to blue-green potassium #Feldspar, and just pretty enough for me to like it despite my default indifference to silicates.

The blue is usually from a smidge of lead, but can also be from iron. Sunshine may colour-boost real amazonite.

#Rhodochrosite, the bubblegum-pink manganese carbonate. I wish I had a UV light to see if it’d fluoresce dark ruby-red for me.

This is a beautifully-preserved mineral; rhodochrosite oxidizes to grubby black under surface conditions.

#Albite & #Quartz, redux

But this time, instead of clusters of little flat blades, albite is a stubby rectangular tower. Not bad for a feldspar!

Twinnnnsss: #Elbaite (#Tourmaline) & #Quartz from San Diego, California.

Crystal twins are when 2 crystals share a lattice, resulting in an inter grown symmetrical pair.

Aside from the undeniable pretty factor (high), it’s a good example of barrel vs prism crystal shapes.

#Fluorite (blue) & #Quartz (white), still no UV light to flight this shit up.

I’m fascinated that instead of growing hexagonal prisms, the quartz has barnacle-like hexagonal hollows. It’s like an inverted crystal! I’m guessing it’s a void of a broken-off other crystal

Moar pink #Rhodochrosite from Sweet Home Mine, Colorado

It seems so unread something this sharp, this geometric, & this vibrantly pink is a totally natural mineral that just kinda... grows, doin’ its own thang.

#Selenite (moonshine pearly #gypsum) curled up into a ram’s horn.

Gypsum is an evaporite, so it can grow in all kinds of flowing forms. Even intellectually knowing that, curling ram’s horns feel like magic.

Spiky puffball of #Mesolite looks like a hedgehog to be! 💚

Hydrated calcium x sodium x aluminum silicate, named for being a compositional middle-ground between #natrolite & #scolecite.

Yes, the fuzzy-puffball look is diagnostic.

#Scolecite is a cousin to the spiky hedgehog — another hydrated calcium aluminum silicate.

It’s as pettable as it looks — roughly as hard as glass so it won’t crumble, with silky-smooth texture.

It’s named for acting like a worm under a blowtorch’s flame, which. Uh. Seems mean?

#Apophyllite, #Stilbite, & #Quartz from India. The thing is, I don’t know which is which!

Apophyllite is a pearly white & exfoliates (sheds layers) if you heat it. Opaque cluster?

Stilbite‘a name means super-shiny-glittery mirror. Maybe it’s grainy base?

Quartz is green bunch?

Absolutely gorgeous clear hexagonal #quartz prisms, and the delightful shadow they cast on the carpet.

Quartz is a silicate (kinda like natural glass).

It’s pretty much the most common mineral on the crust of the Earth. Pick up the nearest rock. Odds are it has quartz in it.

And, uh, a bunch of other minerals.

Like a lot more — @hmns has over 450 minerals on display, not counting their temporary special exhibit of tourmalines I didn’t even get a chance to see before I had to leave. Bah, humbug!

As for the Lester & Sue Smith Gem Vault, I poked in just long enough to bask in the sparkles, but didn’t prioritize minerals that had been cut & polished for maximum artistic shine.

While it was undoubtedly 30min well-spent & the samples gorgeous, it was frustrating labels are just ID & locality.

No geochemistry, no context, no stories, no clear reason why particular minerals were displayed together. If you aren’t an expert already, it’d be impenetrable.