Bismuth Crystals

When I was little I collected rocks and crystals. I loved them. My favorite museum (The Museum of Science in Boston) used to have glass-front cases where you could buy rocks and gems, nestled in little white jewelry boxes with a small card indicating what they were. My mom let me buy one rock every visit. Science museums don’t have these anymore. They just have bullshit wooden bins of tumble-polished generic stones you’re supposed to scoop into a bullshit little leather satchel, without learning anything educational i.e. what the freaking stones are. I hate that.

Anyways, I grew up and my rock collection sat in a Ziploc bags in a Rubbermaid container on the top shelf of various closets for several decades, until last year when we found ourselves moving and interrogating every last possession for its potential to Spark Joy. The rocks Sparked Joy, for sure, mostly after my wife suggested we arrange them all nicely in a vase. Great idea! But first I dug through the bags looking for my favorite rock, the Supreme Joy Sparker, a bismuth crystal colored like the rainbow sheen of an oil slick, with a crazy infinite stairshape structure that looked like something out of an MC Escher painting from outer space. So cool.

But the bismuth crystal wasn’t there! Joy Extinguished. To this day I have no idea what happened to it. I have every geode, every agate slice, every shard of quartz, every chunk of pyrite (Fool’s Gold). No bismuth. Such a bummer. Obviously I immediately Googled to figure out where I could get a replacement, and I learned something amazing: you can grow your own bismuth crystals! Yourself! Kitchen science!!!


So three pounds of 99.99% pure bismuth ingots and three stainless steel butter warmers  from later, I was in my kitchen, ready for smelting (Note: what I did here is not really at all smelting but I like the word b/c it reminds me of one of the best lines from the cinematic classic that is Goldmember).

Which, in turn, reminds me: this is a dangerous activity. If you do this at home you should have all of your arms/legs/members covered with clothing and wear close toed shoes and eye protection and heat proof gloves. I also laid some tin foil around the work area in case of accidental molten bismuth spillage. In fact, I would probably not do this in my kitchen again – the small pots were pretty precarious on my style of burner tops and my wife did not appreciate the smell. If I were to ever do this again, my Coleman stove outside would probably work just as well and might be a better idea.

The pots:



The ingots:




The ingots in the pot, starting to melt:


The initial melt took a while…


Just another warning, this stuff, and the headspace above it, gets really freaking hot. Bismuth melts at 520.6°F / 271.4°C. I was not able to even stir the stuff without oven mitts on. Be very, very careful if you decide to do this.

When it is fully melted it is time for pouring! I basically followed instructions from the following sites:


In summary, I:

  • Heated the bismuth to melting in Pot #1
  • Simultaneously heated empty Pot #2 on another burner
  • Poured the molten bismuth from Pot #1 to Pot #2, leaving the sludgy top skin behind
  • Left Pot #2 on the (turned off) burner to cool, sort of jiggling it from time to time to check the cooling
  • When my jiggles revealed nice crystals had formed around the edges, I poured the remainder bismuth into Pot #3, which I probably should not have done because I just wound up wrecking a perfectly clean pot. More on that later.
  • Let the crystals in Pot #2 cool a bit then chipped them out of the pan


My first crystals were awesome! I am so happy with them!




After the first crystallization I had quite a bit of bismuth remaining, and wanted more. I made several attempts to redo this, although I did need to get creative due to the lack of a perfectly clean receiving vessel. I got a couple of good tiny crystals, in different (more red) colors than the first time. The colors come from bismuth oxides on the surface. That oxidation is good at first, but I suspect became problematic later…


…because after these little babies, all subsequent attempts were a dud. This is really important because all of the websites above are like “don’t worry if you mess up the first time you can just re-melt and try again!” Well, I am here to put tons of pressure on you because you best not mess up the first time. If your experience is anything like mine it’s the only chance you get.

I can think of several  possible reasons the crystals didn’t materialize the next five times I tried:

  • Factors affecting cooling/crystallization rate:
    • I probably never heated the receiver vessel as long as I did the very first time, when the ingots took forever to melt. Cooler receiver would mean faster cooling.
    • Although I did my best to clean/chip/scour the bismuth residue out, the receiving vessels were not very clean, and that may have induced the crystallization of large globs rather than individual crystals
    • For every crystal I removed there was less molten bismuth, which likely led to a slightly faster rate of cooling, which is not great for crystal size
  • Factors affecting purity:
    • The first crystals were highly pure and the residual bismuth I was working with was, in turn, less pure
    • The stuff was just getting disastrously oxidized the more I handled it, which became an increasing problem as I went along
  • Probably other things I am not thinking of

Anyways, the final question is why do these crystals form this way? I don’t know! I’m an organic chemist. But I am a pretty good Googler. Apparently these types of crystals are called “Hopper crystals,” with the stairstep pattern occurring because the rate of crystallization at the edge of the forming crystal is faster than the rate of crystallization on the faces. They also often have cool fractals, which is apparently caused by a phenomenon called “screw dislocation.” Screw dislocation, like many things related to crystal science and inorganic chemistry, is something that I guess if you explain it to me I kind of sort of understand enough satisfy my curiosity, but would never be capable of explaining to someone else. Ever. So don’t ask.

The full haul:


Anyways, the ingots certainly weren’t cheap – if you want a bismuth crystal it’s a lot cheaper and easier to buy one, but also less fun!

References I used:

Crystal growing:

Materials used:

Hopper Crystals:

Screw dislocation:




Wha, WHO?

Soapbox Time:

I am feeling seriously confused. I went to a reception with delicious bacon wrapped scallops and brown sugar sticks and all people could talk about was this stupid WHO announcement. So I just read it all in full and am still totally confused. First of all: Before today, did people think processed meats were good for us?  Me yesterday: “Yeah, I’ll probably die of bacon.” Me today: “Yeah, I’ll probably die of bacon.” Nothing has changed.

Further and probably more importantly, I learned cooked (charred) meat was a carcinogen in college. I went to college more than a decade ago. Scroll down and just look at the dates on the references cited here:

We have known this stuff FOREVER. Why is this news? Why is WHO just getting around to calling red meat a carcinogen now if I literally learned this in 2002?

It’s super sad how slow and muddled the uptake and dissemination of real information is, particularly with respect to food.

Reese’s Piece #1: Peanut Butter Eggs

For those who celebrate it, Happy Easter! By now I hope you’ve had your fill of food and family and church (if that’s your thing) are eagerly anticipating tomorrow when all the candy at CVS is 75% off.

Now, I am not a huge candy person. When dinner is over, I’d trade dessert for a nice cheese course any day of the week. But if you follow me on Twitter, you may be aware that I do have one singular candy weakness, and that is seasonal Reese’s products:

The beauty of seasonal Reese’s products is that select seasonal Reese’s products have a far superior chocolate-to-peanut butter ratio than your standard everyday Reese’s cup. They literally have SO. MUCH. PEANUT BUTTER. If  (1) you can ignore the fact that said “peanut butter” is really a 1:1 peanut butter:sugar paste, and (2) you are far enough down the paleo/low carb rabbit hole that you worship at the altar of all things nut butter, you can basically delude yourself into believing some very insane things, things like “seasonal Reese’s products are the One True Paleo Dessert Food,” and “for a candy, hey, seasonal Reese’s products are a great source of protein and when you think about it, relatively low in carbs, too!” (Don’t worry, I’m all better now).

So yeah, it has been well-documented by candy enthusiasts far more devoted than myself that the Peanut Butter Pumpkins, Trees, Hearts and Eggs are the four pillars of candy greatness to which all other candies aspire to emulate but can never achieve. I say selectseasonal Reese’s products for a reason. Around the holidays the candy market also gets saturated with “miniature” and “snack size” versions of these items with either similar or often WORSE chocolate-to-peanut butter ratios, and let me tell you that buying a bag of the wrong kind of seasonal Reese’s product can just about ruin your day.

It is a vertiable minefield out there, and I am here to guide you.

This is the first in a series of Reese’s pieces in which I will walk you through all of the products in the Reese’s portfolio and let you know the precise(ish) chocolate-to-peanut butter (C:PB) ratios so that you can make an informed decision as a consumer.

We are starting with Easter.


Now as you can see, Reese’s actually offers many Easter-themed products but we are going to ignore miniature cups, Reese’s Pieces, and bunny-shaped itesm, and focus on what’s really important: the eggs. Another note is that I inspected closely, and the “king sized” eggs were merely two regular eggs packaged together, so that item was not purchased.


My wife and I hit up a couple of drug stores and I’m proud to say we were able to hunt down every egg product, and thanks to a nifty plastic egg assortment, we were able to keep costs down to boot! Win-win. Here is what it contained:


So let’s get the tools together and dissect these things.


Item #1: The Regular Peanut Butter Egg


Look at it. Isn’t it glorious?  Let’s get a view of a cross-section:


The Regular Peanut Butter Egg is a classic. I believe that in the end, the Peanut Butter Egg will prevail with the lowest C:PB ratio, because unlike the Pumpkin, Tree, and Heart, it should have the lowest surface-to-volume ratio; there are no silly nooks and crannies for extra chocolate to get caught in. It’s sleek, simple, and sexy.


Upon dissection, two regular eggs gave 39 g of chocolate and 34 g of peanut butter, for a final C:PB ratio of 1.15:1

Item #2: The Snack-Sized Peanut Butter Egg


The snack-sized egg is actually also a favorite around my household because the serving size is a bit smaller, and it makes it a bit easier to pace yourself. The regular egg, while delicious, is also a major commitment. And in cases when one is not quite enough, two are way too much. Two are always way too much. With the snack sized egg, reaching the perfect peanut butter cup serving size is easily attainable. Here is a size comparison:


The C:PB ratio FEELS similar to the regular egg….but is it?

A cross-section:


Three snack-sized cups afforded 29 g of chocolate and 23 g of peanut butter for a C:PB ratio of 1.26:1


Item #3: The Giant Peanut Butter Egg


Admit it, every time you see this you want to buy it. But you don’t, and here are two reasons why: (1) You don’t want diabetes. (2) These things are so dangerous. You have NO IDEA what the insides might hold. You are a skeptical consumer, and you know that Big Candy are bastard money-grubbers at this time of year, and that that egg could have >1 cm thick chocolate walls and hold about the same piddly amount of peanut butter as a single peanut butter cup.

Well, I am happy to report that this is not the case! Just look at this baby:


Admittedly, not exactly the C:PB ratio depicted on the box…


..but Good Guy Big Candy, thanks for not screwing us over on the peanut butter.


The Giant Peanut Butter Egg had 103 g of chocolate and 73g of peanut butter for a C:PB ratio of 1.41:1. It was also by and large the easiest to dissect and I appreciate that.

Item #4: Flat Mini Eggs


These things are bullshit. I mean just looking at them you would know there can’t possibly be any peanut butter in them. And you would be correct:


Eight of these POS petty excuses for Reese’s products afforded 58 g of chocolate and a mere 18g of peanut butter for a straight up appalling C:PB ratio of 3.22:1


Item #5: Round Mini Eggs


Wow! I literally have never seen these before. In real life they look nothing like what is depicted on the website, but I guess they are the same thing? Who knows. They are kind of like smaller versions of Cadbury eggs. They have little holes in them. They are weird. Let’s look inside:


Eight of these bad boys gave 62 g of chocolate and 31 g of peanut butter, for a C:PB ratio of 2:1. I would be displeased about this but they get a pass for being cute and the only Reese’s Egg product that is actually shaped like an egg.


Item #6: White Chocolate Regular Eggs


I’m really not into white chocolate, but if you are, well, whatever floats your boat. Here’s a cross section:


Two of these babies gave 35g of white chocolate and 44g of peanut butter. Wait what? Two White Chocolate Eggs have more peanut butter than two Regular Chocolate Eggs? Maybe? The batteries are dying on my kitchen scale. But yeah, that is what it seems.


The WC:PB ratio on these eggs is 0.8:1. According to my dying scale, these things are more peanut butter than chocolate. Amazing.

Item #7: White Chocolate Snack Sized Eggs


Let’s see if the trend holds up:


Two of these guys yielded 18 g of white chocolate, 18 g of peanut butter. WC:PB ratio is precisely 1:1. Astounding.


Now, if you are anything like me, you are saying: wait. Is there a difference in density between white chocolate and regular chocolate? Is that skewing the measurements? So I did what any normal person would do and melted each chocolate in the microwave and measured the volumes.


18 g of white chocolate melted to just under 4 tbsp


19 g of dark chocolate melted to just about 4 tbsp

I’m not a savage or anything so I’m not about to mix metric with English units here, but the math in my head says those densities are about the same.


So there you have it. Here are the final rankings, this time expressed in grams of peanut butter per gram of chocolate:

  • Regular White Eggs: 1.25
  • Snack White Eggs: 1.00
  • Regular Eggs: 0.87
  • Snack Eggs: 0.79
  • Big Egg: 0.70
  • Round Mini Eggs: 0.50
  • Flat Mini Bullshit Eggs: 0.31

Now go forth and buy discounted candy armed with SCIENCE!