GROW THE ANGULAR, COLORFUL BISMUTH CRYSTALS YOU SEE IN MINERAL SHOPS USING BISMUTH OBTAINED FROM COMMON COMMERCIAL PRODUCTS AND A LITTLE HEAT!

 

 
WARNINGS: FIRE IS HOT.  SO IS METAL THAT HAS BEEN IN CONTACT WITH FIRE.  CONTACT WITH ACTUAL FIRE, OR METAL THAT CAN BEEN IN CONTACT WITH FIRE CAUSES NASTY THINGS CALLED BURNS.  BURNS ARE KIND OF LIKE GETTING HIT BY A TRUCK, BUT WORSE.  DON'T SAY I DIDN'T WARN YOU.


D
ESCRIPTION

MANY ARE TEMPTED TO CHARACTERIZE SOLIDS INTO TWO CLASSES; THOSE THAT CRYSTALLIZE, AND THOSE THAT DON'T.  CRYSTALLINE SOLIDS DISPLAY A CERTAIN LEVEL AND STRUCTURE ON THE ATOMIC LEVEL.  THIS OFTEN APPEARS MACROSCOPICALLY AS A LARGE CRYSTAL.  OTHER MATERIALS DO NOT DO THIS, AND THEY ARE CALLED AMORPHOUS.  AMORPHOUS SOLIDS SIMPLY FORM RANDOMLY, WITHOUT A STRUCTURED SHAPE.

IN LIGHT OF THIS DESCRIPTION, METALS APPEAR TO BE AMORPHOUS, BUT IN FACT THEY ARE NOT.  MOST METALS HAVE A WEAK CRYSTALLINE STRUCTURE.  THE EASIEST EXAMPLE, FOR VIEWING PURPOSES, IS BISMUTH, WHICH IS OFTEN FOUND IN CRYSTAL FORM IN SPECIALTY SHOPS.  BISMUTH IS KNOWN FOR ANGULAR, COLORFUL CRYSTALS.  THE COLOR COMES FROM THE OXIDATION LAYER FORMED WHEN COOLING BISMUTH COMES IN CONTACT WITH AIR.

THIS EXPERIMENT WILL DEMONSTRATE A CHEAP WAY TO FORM BISMUTH CRYSTALS AT HOME.  NOTE THAT YOU PROBABLY WON'T BE ABLE TO ACHIEVE THE RAINBOW COLORS, DUE TO THE IMPURITIES IN THE BISMUTH, AND THE METHOD I'M USING.

NOTE:  I REALIZE THAT THIS APPEARED IN POPULAR SCIENCE; I NOTICED SHORTLY AFTER I FINISHED MY EXPERIMENT.  GREAT MINDS THINK ALIKE, I SUPPOSE.
 

MATERIALS        

-AN EMPTY POP CAN (A FULL ONE CAN BE USED, PROVIDED YOU DRINK IT FIRST)
-BISMUTH SINKERS (EAGLE CLAW NONLEAD SINKERS WORK - WALMART)

EQUIPMENT        

-A STOVE OR GAS TORCH

PROCEDURE

 

WHY?

1.  GO TO WALMART AND BUY SOME BISMUTH SINKERS.  I FOUND EAGLE CLAW NONLEAD SINKERS TO WORK FINE, AND ARE AVAILABLE AT WALMART.

THINGS LIKE BB GUN SHOT AND FISHING WEIGHTS ARE TRADITIONALLY MADE FROM LEAD.  AS HIPPIES TAKE OVER THE COUNTRY, HOWEVER, LEAD IS BEING TAKEN OFF THEN SHELVES.  BISMUTH IS A GOOD SUBSTITUTE BECAUSE IT IS NICE AND DENSE, AND ALSO SOFT.
2.  CUT THE BOTTOM OFF OF YOUR EMPTY POP CAN.  LEAVE ENOUGH OF THE WALL SO THAT IT CAN SIT FLAT ON THE STOVE. WE'RE MAKING A GHETTO CRUCIBLE HERE.  ALUMINUM, ALTHOUGH A LOW MELTING METAL, STILL HOLDS UP OK AT THESE TEMPS, AND TO BISMUTH.
3.  THROW THE SHOT INTO THE CAN AND SET IT ON THE STOVE.  TURN UP THE BURNER SO THAT IT HEATS THE BISMUTH, AND WAIT. FIRE IS LATIN FOR 'MEGA SUPER HOTNESS', AND YOU CAN USE IT TO MELT THE BISMUTH.
4.  IT WON'T TAKE LONG TO MELT THE BISMUTH.  NOTICE ITS TURNING ORANGE AT THE EDGES; THIS IS OXIDATION, AND IT MESSES UP OUR EXPERIMENT, BUT WE CAN DEAL WITH IT LATER. OXIDATION MEANS THE HOT BISMUTH IS REACTION WITH THE AIR.  IT FORMS A LAYER OF KINDA PAPERY NASTINESS.
5.  KEEP WAITING.  NOTICE THE OXIDATION.  
6.  FINALLY THE MELT IS DONE.  POKE THE CENTER WITH A WOODEN TOOTHPICK TO MAKE SURE ITS ALL LIQUID. BE CAREFUL WITH THE TOOTHPICK, DON'T SPLATTER THE BISMUTH.  THE METAL WON'T LIKELY HURT ANYTHING BUT YOU, WHICH IT WILL HURT VERY MUCH.
7.  KEEP THE HEAT ON THE BISMUTH, AND BREAK A TOOTHPICK AS SHOWN. WE'VE JUST MADE A OXIDATION REMOVAL TOOL.
8.  QUICKLY, AND CAREFULLY, SWIPE THE FLATTENED PART OF THE TOOTHPICK ACROSS THE BISMUTH SURFACE.  THE WOOD WILL CHAR A BIT, ITS FINE. THIS REMOVES THE THIN OXIDE COATING, LEAVING A NICE CLEAN METAL SURFACE, AS SHOWN.
9.  NOW COMES THE HARD PART, SO LISTEN CAREFULLY.  SHUT OFF THE HEAT AND WAIT EXACTLY 30 SECONDS (ASSUMING YOU USED THE SAME QUANTITIES THAT I DID).  AFTER 30 SECONDS, POKE THE POP CAN LID WITH THE TOOTH PICK SO THAT THE BISMUTH JIGGLES A BIT. 

YOU'RE LOOKING FOR THE BISMUTH TO JIGGLE, BUT ONLY IN THE CENTER; YOU WANT THE OUTSIDE TO BE SOLID.  THIS HALF-MOLTEN STATE LASTS ABOUT 5 SECONDS, SO BE QUICK.  DON'T POKE TOO OFTEN, OR TOO HARD, AS YOU CAN CAUSE IT TO CRYSTALLIZE FASTER.

WHEN YOU CATCH IT IN THE SEMI-SOLID STATE, QUICKLY FLIP THE POP CAN LID, DUMPING THE BISMUTH ONTO THE SURFACE OF THE STOVE.  DON'T WORRY, YOU WON'T HURT ANYTHING.

THE CRYSTALS GROW UNDERNEATH THE LIQUID BISMUTH.  IF YOU WAIT TOO LONG, THE BISMUTH WILL HARDEN RIGHT OVER THEM, AND YOU WON'T SEE A THING.  DUMPING OUT THE LIQUID CORE WHILE ITS STILL MOLTEN WILL REVEAL THE CRYSTALS FORMING BENEATH IT.
10.  IF EVERYTHING WENT RIGHT, IT WILL LOOK LIKE THIS!  

RESULTS

SOME CLOSE-UPS OF THE SUCCESSFUL CRYSTALS ARE SHOWN BELOW.  NOTE THAT IT WILL VERY LIKELY TAKE A FEW TRIES BEFORE YOU SUCCEED IN GETTING THE TIMING RIGHT.




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