Goldwork for the Golden Calf

Moses said to Aaron, “What did this people do to you that you have brought such great sin upon them?”

Aaron said, “Let not my lord be enraged. You know that this people is bent on evil.

They said to me, ‘Make us a god to lead us; for that man Moses, who brought us from the land of Egypt—we do not know what has happened to him.’

So I said to them, ‘Whoever has gold, take it off!’ They gave it to me and I hurled it into the fire and out came this calf!”

Exodus 32:21-24

When the Hebrews despair of ever seeing Moses again, they coerce Aaron into giving them a substitute, so he makes a calf out of gold. But not even Moses believes his brother’s excuse about a magic fire that turned jewelry into an animal statue. In earlier verses we see Aaron crafting the calf, but it’s not very clear exactly what he’s doing.

And all the people took off the gold rings that were in their ears and brought them to Aaron.

This he took from them and cast in a mold and made it into a molten calf.

Exodus 32:3-4

This is Sefaria’s version but they put in the footnotes that the term “cast in a mold” can also mean “foundry” and that others have translated it as “fashioned it with a graving tool.” Chizkuni describes it in a way translated to English as “he shaped it.”

ויצר אותו, “he shaped it,” the expression יצר, used by the Torah here to describe what Aaron did with the golden jewelry he had received, is based on the word: צרר, “to make a bundle of something, to treat it indiscriminately, or to compress it.”

Chizkuni, Exodus 32:4:1

Can You Melt It?

Gold certainly can be melted down then cast with a mold. The problem is that it melts at the very high temperature of 1,948°F (1,064°C) (with slight variations depending on the karat). Most wood cookfires are around 1/3 of that. A large wood fire, a bonfire, can get much hotter. With the right wood and conditions, it can get up to 2,012°F (1,100°C), or just hot enough. Charcoal can burn even hotter. As it happens, the Hebrews roasted a bunch of large animals just before Moses ascended the mountain (almost 40 days earlier) so there should be plenty of charcoal left.

Another problem is there really isn’t that much wood around. Brush yes, not not trees. They’re in an extreme desert at fairly high elevation and any wood they brought is for the mishkan and carts. They might also have bamboo, which they’d use for tent frames, but they might be able to spare some for fires. Both tree wood and bamboo burn much hotter as charcoal.

I see the Hebrews almost exclusively using dried dung as fuel. They have copious amounts of it (with plenty of brush to get the fire going). It’s also something traditionally used in many cultures, including in Egypt.

In Egypt dry animal dung (from cows & buffaloes) is mixed with straw or crop residues to make dry fuel called “Gella” or “Jilla” dung cakes in modern times and “khoroshtof” in medieval times.  Ancient Egyptians used the dry animal dung as a source of fuel…Temperatures of dung-fueled fires in an experiment on Egyptian village-made dung cake fuel produced “a maximum of 640°C (1,184°F) in 12 minutes, falling to 240°C (464°F) after 25 minutes and 100°C (212°F) after 46 minutes. These temperatures were obtained without refueling and without bellows etc.”

Dry dung fuel. Wikipedia.

This is not far off from the temperatures one would get from a regular wood fire (a cookfire, not a bonfire). Starting off with a dung fire and then switching to charcoal might actually work to melt gold. Another fuel source is bone, which they’ll also have plenty of in the fire pits after the sacrifices. They seem to burn at similar temperatures to wood.

Forcing Air

What you’d really want to use though is bellows or blowpipes or something else to increase the temperature. In modern times some people use propane blowtorches and the gold melts in under a minute.

It is possible to reach very high temperatures with very basic technology like blowpipes. Egyptians were melting gold with blowpipes since the early 3rd millennium BC.

An answer from How did ancient civilizations melt gold if gold melts over 1064ºC? Quora. 2019.

A picture from the Old Kingdom (long before the supposed Exodus times) shows six people using blowpipes to keep the gold melting crucible hot enough. While quite impractical compared to bellows or modern equipment, it’s completely doable for a one-time emergency statue such as the Golden Calf.

In the New Kingdom, not long before the time of the Exodus, the Ancient Egyptians were using pot bellows.

Working pot bellows in ancient Egypt, about 1450 BC. BC. By about 1800 BC, Babylonian and Hittite metalworkers were using a pot bellows to smelt copper. You stretched leather over the top of a clay or limestone pot and pulled the leather top up with a string or a stick to fill the pot with air, then stomped on the pot to push the air out into the fire, over and over. A pot bellows turned out to create enough heat so you could smelt iron ore and get usable iron out of it. This same bellows could also be used to melt glass, and almost immediately people in Syria and Lebanon started to use pot bellows to make the first core-formed glass bottles and glass beads. Soon New Kingdom Egyptians were also using pot bellows to smelt metal, and from there they spread slowly to West Africa.

Working pot bellows in ancient Egypt. Quatr.us – Simple History and Science Articles. Facebook. Jan 23, 2018.

Would the Hebrews Have the Knowledge & Equipment?

The short answer is yes. We know they have both because, right after Moses returns with the second set of tablets, they get started on building the Mishkan and the priestly garments. Both of these involve a lot of complex metalwork. They not only had the metal (much of which was given to them by their “neighbors” just before they left Egypt) but they would have brought the tools. We also know that Ancient Egypt had the skills and technology for precious metalwork, including gold, silver, and copper.

How Do You Shape It?

Gold can be poured into molds, including lost wax casting, something done by the Ancient Egyptians. But honestly, I don’t think that the Golden Calf was very well done. Aaron didn’t want to make it and no one probably wanted to help him, least of all the trained metalworkers among the Hebrews. And there wasn’t time. The Hebrews who threatened Aaron until he agreed to replace Moses weren’t going to wait a year (or even a week) for a piece of art.

The Torah says the Calf was finished the same day that Aaron collected the gold, with a festival the day after. Aaron and whatever helpers he had would most likely melt the gold and pour it into rough molds, then shape it with hammers and other tools and stick it all together. Gold is soft enough that they could possibly even skip the melting step and just pound it.

If the gold is melted, it will cool down fairly quickly, even faster with water. So the timeline works, as long as you don’t mind a crude statue that barely stands on its own. And I think no one minded.

References:

• Chizkuni on Exodus. Hezekiah ben Manoah, French rabbi and Bible commentator of the 13th Century.
• Gold. Wikipedia.
• How Hot Is a Bonfire?  April 26, 2018.  Gabriella Munoz.  Sciencing.
• Dry dung fuel. Wikipedia.
• How did ancient civilizations melt gold if gold melts over 1064ºC? Quora. 2019.
• Tomb of Mereruka. At the Ministry of Tourism and Antiquities.
• Metals Used in Metal Sculpture.  Weld Guru.  June 28, 2021. Jeff Grill.
• Experiments in Bone Burning.  Megan Glazewski, author pp. 17-25. Oshkosh Scholar, Volume I, April 2006.
• Bellows. Wikipedia.
• Working pot bellows in ancient Egypt. Quatr.us – Simple History and Science Articles. Facebook. Jan 23, 2018. Plus an article, What is a bellows? Who invented the bellows?