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How Money Works

Shells, Salt, and Strange Currencies

Ages 8–12 20 min read Beginner

Before gold coins and paper notes, humans used some truly surprising things as money. Seashells, salt, giant stones, tea bricks, cattle, and even human skulls have all served as currency.

Understanding why these things were chosen reveals what money actually is.

The Weirdest Money in History

Cowrie Shells

Small, shiny shells from the Indian and Pacific Oceans were used as money across Africa, Asia, and Oceania for over 3,000 years. They were durable, hard to counterfeit, and easy to carry. The Chinese character for "money" (貝) is based on the cowrie shell.

Salt

Roman soldiers were sometimes paid in salt — which is where the word "salary" comes from (Latin: salarium). Salt preserved food before refrigeration, making it genuinely valuable.

Rai Stones (Yap)

On the island of Yap in Micronesia, people used massive limestone discs — some 3 metres across and weighing 4 tonnes. They couldn't be moved, so ownership was tracked by the community's memory. Sound familiar? It's essentially an early blockchain.

Tea Bricks

Compressed blocks of tea served as currency in Central Asia, Siberia, and Mongolia well into the 19th century. They could be broken apart, traded, and — in emergencies — brewed and drunk.

Wampum

Indigenous peoples of North America used strings of shell beads (wampum) not just as money but as record-keeping devices and diplomatic tools.

What Makes Something "Money"?

Looking at these strange currencies reveals that money needs to be:

  1. Accepted — everyone agrees it has value
  2. Durable — doesn't rot or break easily
  3. Portable — you can carry it (Yap stones are the exception!)
  4. Divisible — you can break it into smaller units
  5. Scarce — not so common that it's worthless

Today's money (digital numbers in a bank computer) meets most of these criteria — except it's not scarce. Central banks can create unlimited amounts. That's a significant difference from shells and salt.

Tonight's Question

"If we had to invent our own family currency, what would we use? What makes something good money?"

Have fun with this. Could you use Lego bricks? Marbles? Stickers? What properties would work?

Design Your Own Currency

  1. As a family, design a new form of money.
  2. Consider: what material? How is it divided? What prevents counterfeiting? What gives it value?
  3. Create physical tokens (paper, clay, decorated stones — anything).
  4. Use your currency for a "family economy" this weekend — earn it through chores, spend it on privileges.
  5. Discuss at the end: what worked? What didn't? What did you learn about money?

Go Further

  • Research: How did Yap islanders track ownership of stones too large to move? Compare to how Bitcoin tracks ownership.
  • Museum: The British Museum has a virtual "History of Money" exhibit online.
  • Book: Money: The True Story of a Made-Up Thing by Jacob Goldstein (2020).
  • Question: If money is whatever people agree it is, could anything become money? What about social media likes?

What We Simplified

  • The "salary from salt" etymology is debated. Some historians think salarium referred to money given to soldiers to buy salt, not salt itself.
  • Many of these currencies coexisted. Societies often used multiple forms of money for different purposes.
  • Context matters enormously. What works as money in a small island community doesn't work for a global economy.

Sources

  • Goldstein, J. (2020). Money: The True Story of a Made-Up Thing. Hachette.
  • Weatherford, J. (1997). The History of Money. Crown Publishers.
  • Fitzpatrick, S.M. (2003). "Banking on Stone Money." Archaeology, 56(2), 18-23.
  • Yang, B. (2011). "The Rise and Fall of Cowrie Shells." Journal of World History, 22(1), 1-25.

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