Color is a tantalizing trend. Impossible Burger had difficulty with the FDA’s regulatory hoops due to man-made soy proteins’ blood-red colour. (1) Cannabis extracts went from black to golden, and then to clear. But now, a highly purified cannabis extract – known as THC diamonds – has turned inquisitively and brilliantly blue as well as an odd sea salt pink. 

Blue thc diamonds have a pink companion
Blue diamonds of THCa. Photo courtesy of Willy Billy Tek

Crossing off terpenes and flavonoids can make blue and pink THC diamonds

These THC diamonds are apparently 99.9% pure, but THCa has no color. We asked an expert to clarify, but more on that shortly. Blue and pink THC diamonds can allegedly be caused by something other than the purple flavonoids known as anthocyanins.

Another blue contaminant in cannabis extracts is azulene, known to cannabis distilleries as ‘smurf blood‘. (2)

Lulu Berlu

This brightly blue colored substance is created by dehydrogenating terpenes, so it is semi-synthetic and considered an offputting contaminant. Yet, smurf blood doesn’t explain pink cannabis diamonds. If it is not azulene, where else do brilliant pigments come from in cannabis cultivation and processing?

One person responsible for blue cannabis diamonds claimed the crystal structure of their THC is the cause of different colors, not a contaminant.

When you #AskAnExpert about these blue and pink THC diamonds

It turns out, Dr. Roggen, Ph.D., and founder of a cannabis research lab, CBDV, can make colored THC crystals in his lab. Rather than flaunt them as a new billion-dollar piece of matter, blue and pink THC diamonds would simply be considered chemical waste after the experiment is complete. Thankfully, he is our resident scientist. So, we asked Dr. Roggen for his opinions on what can create color in crystallized THC extracts, and now we know more about cannabinoid salt.

Have you heard of these new blue and pink cannabis diamonds?

Breaking Bad was so 2000s. Now, they do blue cannabis – seriously? If there is color – like blue – there is something else in there other than THC. It’s not THC or THC-acid, it’s something else. So, three things can make color [in THC extractions].

The first thing is metal contamination. So metals have vibrant colors – like gold, silver, or copper. There are also metal salts that can be blue. So, you definitely don’t want those. Organic ions or radicals can have color, but radicals don’t like to hang around long, so they are not really a thing. Organic ions can be stable and they would be in the form of organic salts, like THCa with a sodium counterion. And the third option are organic molecules with extended aromatic systems, like azulene. But those would be contaminated and should not be in pure THCa crystals.

Dr. Markus Roggen
chemical structure of salts
“And if our reduction is not stereospecific, then how can our product be enantiomerically pure?” Heisenburg, Boxcutter, Breaking Bad.
Photo courtesy of Infobytes TV.

Nic salts – meet THC salt

By organic salts – do you mean cannabinoid salts? I guess THCa is an acid. And, salt is an acid that has had its hydrogen taken away, so to speak. So, does THCa-salt make sense chemically?

Yes, it is relatively easy and cannabinoid salts can have colors.

Salts are not to say bad. But, I would like to know a bit more about it. Why would one want to have salts in the first place? A related example, nicotine, and nicotine-salts are two different versions of the same thing. And nicotine salts have been used in vaporization in e-cigarettes because they absorb better. But, eventually, they end up in the human body. I wouldn’t be okay with them producing salts or something to just make a color because I would not know what they would do to the body.

Dr. Roggen

Cannabinoid-salt tek

Salts are basically two ions sticking together. So, you have a cation and an anion. And, to think of a salt, one of the things, the anion, is your THCa or your former THCa, and then you have a cation. If you think of THCa there are oxygens on this molecule.

OH groups are always in a good position to think about salts because you can remove the hydrogen relatively easily from the alkyl group. And then you’re left with a negative oxgen (O-), which is your anion, or your negative ion. The hydrogen turns into (H+), your positive ion [cation], but they will combine to the OH-alkyl group so quickly that you never have a salt. You have a covalently bonded structure.

So, if you remove the hydrogen (H+) and stick something else in the reaction vessel that also has a positive charge that doesn’t bind back onto the oxygen – you get salt. So, you could remove the (H+) [from the OH group] and add another cation.

Dr. Markus

Dabs from a chemist’s trash bin

What other substances, or metals, (cations) can replace a hydrogen atom in the THC-acid molecule? In other words, what chemicals can turn THCa into a salt or a covalently bonded structure?

Sodium, magnesium, and more complicated things. That would allow it. But, I am just spitballing here! We know, to some experience, you have that in the supermarket if you have ever bought antiacids powders or sport drink powders? That is often magnesium or sodium citrate. These are the salts of citric acid. So, someone took the hydrogen away [from citric acid] and replaced it with magnesium. 

Dr. Roggen

The producer claimed they can make any color of THC diamond. So, the color just depends on what metal or other substance they used to replace the hydrogen in the OH group.

The question is, why would you want to do it [with THC]? There are a whole host of reasons why one would want to do this. If they are reasons for it – I don’t know. And my problem is most of the actors in the industry who do those things, don’t have an understanding of what they are doing, and so I don’t like them doing it.

For example, I can do this. But, I am fully aware I don’t understand what the new compounds do to a human system. I can make blue and pink THC diamonds in my lab but then I put this into my chemical waste. You DON’T FEED IT TO SOMEONE!… I am very cautious of this.

Dr. Roggen

An unknown realm of THC

CBN has both aromatic rings conjugated, but it is still not a large enough aromatic system to produce color, unlike azulene. THC-acid, on the other hand, has only one aromatic ring.

What is the third way to make THC diamond produce color? Can you change the molecule somehow that it will refract blue and red light?

So, THC has this one (aromatic) six-membered ring with multiple bonds in there; it’s basically an aromatic system. But, as a shorthand, one ring is not enough to produce visible color. So, you would have to extend [THCa’s] aromatic system.

CBN is not blue [naturally]. So, you would need to pack on more aromaticity to bring THCa to a color. But, now we have a completely new molecule. New molecules do new things and I don’t know what they do. 

Dr. Roggen

You were tickled D8 yesterday, why so Copper (III) today?

Can the molecular structure be changed by a metal contaminant? Does something like Copper (III) convert CBDa to THCa?

So, yes you can convert CBDa to THCa. Metal catalysts can do that, maybe not copper (III) directly, but isomerization can be metal-catalyzed. That is some fancy chemistry.

Dr. Roggen
copper hydroxide in blue and pink THC diamonds
Copper (II) hydroxide. By Nebraska Bob. Wikipedia.

Can a metal catalyst help THCa crystals grow? (SIC)

It wouldn’t catalyze a crystallization. Catalyst means it decreases the activation barrier.

Crystallization needs a seeding. So, you can use a metal seed; you have like a small prick, or cube, of a metal that you drop in your reaction vessel or in your solution. And then it seeds the crystals around it. That can be done. Just having a metal seed wouldn’t give enough color to the system to make it blue in total, though. You would have to throw in a lot of metals to keep that color. And again, you shouldn’t do it either.

1.) Metal contamination – I don’t like. 

2.) [Cannabinoid]-salts: not sure about it. 

3.) New molecules: definitely no.

Dr. Roggen on blue THC crystals

Thank your time Dr. Markus Roggen. End of phone call.

Blue and pink thc diamonds might come pesticide contaminants
Polychlorinated (Cu II) phthalocyanine is added to a mineral oil approved for use as a pesticide in cannabis production. This intensely green chemical is a complex of copper (II).

Do you think blue and pink THC diamonds are natural, contaminated, or a cannabinoid-salt? And stay tuned for a deep dive into the fancy chemistry that is allegedly being used in secret across the United States to produce other, less than natural forms of THC.

Title photo courtesy of Breaking Bad.


  1. FDA Announces Effective Date for Final Rule Adding Soy Leghemoglobin to List of Color Additives Exempt from Certification. Dec 17, 2019. FDA. Accessed Feb 20, 2021.
  2. M. Finley, Cannabis Science and Technology3(4), 52–53 (2020).
  3. US20150038567A1