A final experiment: Gold imitation with chalcopyrite

Dagmar Wujastyk

Gold imitation with chalcopyrite

We have come to the final experiment of this series!

This recipe from the Rasaprakāśasudhākara seemed particularly simple. It doesn't even involve roasting the ingredients in a furnace, and only uses four ingredients: Chalcopyrite, sour gruel, a mystery ingredient, and water. Here's the recipe, with the problematic ingredient highlighted in bold:


सुवर्णमाक्षिकं स्वेद्यं कांजिके दिवस्त्रयम् /

चर्मरङ्ग्या रसेनैव मर्दयेद्दिनसप्तकम् /

जलेन धौतं तावच्च यावद्धेमनिभं भवेत् //८//


Chalcopyrite should be steamed in sour gruel for three days.

One should triturate it for seven days with the juice of carmaraṅgī.

It is washed with water until it resembles gold.


The main ingredient is chalcopyrite - also known as fool's gold! And more recent research has shown that chalcopyrite in fact contains real gold, albeit only traces.

But what is carmaraṅgī? I could not find it anywhere in any of my reference works, so Andrew asked a Vaidya friend who thought it was star fruit.


The recipe thus involved three fairly simple, if time-consuming, steps:

1) Three days of steaming the chalcopyrite in sour gruel (which Andrew had to make first)

2) Seven days of triturating it in star fruit juice

3) Washing it in water.


Easy peasy.


1) Steaming

The steaming procedure should be familiar to all who have been following our experiments by now: You fill a pot with sour gruel. Sour gruel is just fermented rice water (you can also use other grains, which are boiled, and then let sit to ferment). You place the chalcopyrite in a cloth bag and suspend it from a stick into the gruel, so that it doesn't touch the bottom or the sides of the pot. The pot is heated from below, keeping the gruel on a low boil. The recipe calls for a three-day-steaming, which requires quite a bit of refueling of the stove and occasional refilling of the pot with sour gruel.

[Chalcopyrite, also called "fool's gold", before steaming]

[Chalocpyrite, enclosed in a cloth, and suspended into a pot filled with sour gruel]

[The swing-apparatus (dolāyantra)]

It's hard to say what this steaming or boiling does to the chalcopyrite - it looked more or less the same afterwards. Perhaps it had slightly more shine? And maybe it became a bit more porous in the steaming process.

[Chalcopyrite, after steaming]

In any case, chalcopyrite is a material that is fairly easy to break down in an iron mortar. Andrew crushed the steamed chalcopyrite pieces in his mortar until it all was a fine powder.

[Coarsely crushed chalcopyrite]

Time for step 2!


2) Trituration with star fruit juice

Andrew bought some star fruits and made juice out of them. A juicer would have been handy for this, but for lack of one, Andrew grated the star fruits into a pulp, which he then passed through a cloth. Voilà, star fruit juice.

He then added the juice to the chalcopyrite, and started grinding them together. The recipe says to do this for seven days.... but ain't nobody got the time.

[Finely ground chalcopyrite with star fruit juice]

Well, Andrew did triturate the mixture several hours every day for seven days, adding more star fruit juice as needed. A brown-grey sludge was the result, and we were not certain that this was going to be a success. Our last experiment! Was it all going to end with a whimper, rather than a bang? Andrew noted that he was a bit doubtful about the star fruit juice.

After seven days of grinding, it was time for step 3:

3) Washing with water

This step was fairly easy, as any remaining star fruit juice could be diluted with water and then poured off. The result, however, was not very convincing:

[Slightly glittery chalcopyrite]

[Distinctly ungolden chalcopyrite]



A second attempt

We reconsidered the star fruit juice. I did another search for carmaraṅgī and this time did find a reference. This was in Bhagwan Dash's Materia Medica of Ayurveda: Based on Madanapala's Nighantu (page 85), which lists carmaraṅgī as a synonym of Luffa cylindrica - sponge gourd.

This somehow seemed an unlikely ingredient. It also proved to be surprisingly difficult to source in the UK. In any case, Andrew had in the meantime consulted another Rasashastra Vaidya (Dr Parth Kale), who advised that the substance in question was Cassia auriculata, or Senna auriculata: Tanner's Cassia. This was, however, not reading carmaraṅgī, but carmaraṅgā. Not an impossible emendation of the reading, though one would have to read carmaraṅgā and rasena as a compound for the metric structure (16 syllables per line) to work - there would be one syllable too many with carmaraṅgāyāḥ. (Not that the text is entirely consistent in its metre, anyway).

Now, Tanner's Cassia struck us as a likely candidate, given its colouring properties (you can use it like Henna, to dye your hair). And, as it happened, Andrew already had some. That is, he had dried Tanner's Cassia leaf powder, which we could mix into a paste and use instead of fresh juice. So we decided to go with that. And yes, it was a bit annoying to do all that grinding again. Also, we cheated, and reused the already steamed and ground chalcopyrite. And there may have been somewhat fewer hours of grinding. I couldn't possibly say.....

[Tanner's Cassia powder]

It became clear right from the start that this was going to look very different. The chalcopyrite-Tanner's Cassia mix was still a brown goo, but one with quite visible golden specks in it!

The day of washing arrived, and this time, washing the Tanner's Cassia off the chalcopyrite was a bit more involved. However, as the chalcopyrite progressively became cleaner, the more it shone! Though not exactly like gold. It ended up a paste that resembled a silvery-golden metallic paint. It was still a pretty convincing result and we were pleased.

But what would an alchemist do with this? Given that the paste already looked like paint, we thought it might have been used to coat objects. But how to keep it to stick? We tried out mixing it with egg tempera, but that didn't work out: The chalcopyrite discoloured and looked quite brown.

[Chalcopyrite, mixed with egg tempera. Not very golden anymore.]

In the meantime, the remaining chalcopyrite paste had lost much of its lustre, just by being exposed to the air. A dull grey powder remained, with just a few sparkles in it.

So there we are: This was a rather transient result.

As with several of the other recipes, we wonder whether there is something we are missing, some crucial bit of extra information. Maybe an extra line with some instructions on how to preserve the sheen. But perhaps just an explanation how this was supposed to be used. Perhaps we should have started with a more golden-looking piece of chalcopyrite? Chalcopyrite can, by itself, look quite golden! But then, what would have been the point of the procedure?

[Would a piece like this have made the difference?]

Surely the idea was to make chalcopyrite look *more* like gold, rather than just the same as before? The recipe just states the chalcopyrite "is washed with water until it resembles gold". So, in a way, no particularly spectacular outcome is anticipated - though perhaps a more stable one?

And thus, we do indeed end on somewhat of a whimper....


Well, the ancient Indian alchemists did warn us:

The slow minded person who performs alchemical practice

without taking a guru meets with no success.

His acts are like the money one makes in dreams. (Rasārṇava 1.55)


Here is the film of our last experiment with its brief moment of success:





A final experiment: Gold imitation with chalcopyrite

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