Everything Everywhere Daily

Episode: Gemstones (Encore)

Host: Gary Arndt
Air date: October 5, 2025

Episode Overview

This encore episode explores the fascinating world of gemstones, delving into their geological origins, historical significance, and cultural uses. Gary Arndt walks listeners through the science behind precious and semiprecious stones, their stories across continents and centuries, and how they today remain woven into traditions like birthstones and jewelry.

Key Discussion Points & Insights

1. What Is a Gemstone?

• Definition and Composition (03:11)
  • Most gemstones are high-quality minerals with a crystalline structure.
  • Some commonly considered gemstones aren't technically minerals but are classified as such due to rarity and beauty.
• Quote:
  • "Some very common minerals can be considered gems if they're large enough and high enough quality. However, the term gemstone can be a bit of a misnomer as some gemstones are not in fact minerals at all." — Gary Arndt [03:18]

2. Precious vs. Semiprecious Gemstones

• Precious Gemstones:
  • Only four: Diamonds, rubies, emeralds, sapphires.
  • Historically, there were five "cardinal" gemstones, with amethyst once among them.
• Semiprecious Gemstones:
  • Over 200 types (depending on definition), valued for beauty, rarity, and cultural significance.

2.1 The Four Precious Gemstones

• Diamonds (04:07)

  • Pure crystalline carbon created under intense heat and pressure.
  • First discovered in India; later in South Africa and Brazil.
  • Colorless but can contain other hues due to impurities.

• Rubies (04:34)

  • Gem-quality corundum (aluminum oxide).
  • Red color from chromium impurities.
  • “The word ruby comes from the Latin word for red, ruber.” — Gary Arndt [05:18]
  • Key sources: Myanmar, Thailand, Madagascar, Kenya, Tanzania.

• Sapphires (06:00)

  • Also a variety of corundum.
  • Blue color from titanium and trace elements like iron, cobalt, etc.
  • No fixed distinction: Some pink gems might be classified as either rubies or sapphires.

• Emeralds (06:53)

  • Deep green; made from high-quality beryl.
  • Color from chromium or vanadium impurities.
  • Ancient sources: Egypt, India, Austria; modern epicenter: Colombia.

2.2 Cardinal Stone: Amethyst (History & Decline)

• Amethyst (07:53)
  • Deep purple quartz, colored by iron and radiation.
  • Once highly prized due to the rarity of purple dye in antiquity; associated with royalty.
  • Devalued to semiprecious status after large Brazilian finds.
  • “If you’ve ever seen a geode, a rock filled with purple crystals, those are amethyst.” — Gary Arndt [08:34]
  • The largest geode: Empress of Uruguay (3.27m, valued at $190,000).

3. Semiprecious Gemstones: Notable Examples

• Turquoise (09:20)

  • Bluish-green hydrated phosphate of copper and aluminum.
  • Soft, less durable; first found in Iran, now also in southwestern USA and China.
  • "That is why it is so associated with southwestern jewelry and designs." [09:55]

• Opal (10:10)

  • Amorphous silica formed with water; not a mineral.
  • Famous for 'opalescence'—the ability to flash color.
  • Major source: Australia, specifically Coober Pedy.
  • Personal anecdote: Gary shares his experience opal mining in Coober Pedy—unique for its random holes rather than structured mines. [11:02]

• Peridot (11:39)

  • Gem-quality olivine, produced in Earth's mantle and brought up by volcanoes.
  • Common in Hawaii (visible as green flecks in lava).
  • One of the few gemstones also found in meteorites.
  • “Peridot has also been found in meteors, making it one of the only extraterrestrial gemstones.” [12:20]

• Aquamarine & Topaz (12:40)

  • Aquamarine: Blue-green beryl, abundant and inexpensive.
  • “You can find 2-inch aquamarine crystals on Amazon for under $10.” — Gary Arndt [12:54]
  • Topaz: Aluminum fluorine silicate, variable colors.
  • Blue topaz is rare naturally but can be created with heat/radiation treatment.

• Lapis Lazuli (13:34)

  • Not a mineral, but a deep blue metamorphic rock.
  • Prized in antiquity (Egypt, Renaissance art pigment ultramarine).
  • Oldest mines: Badakhshan, Afghanistan.

• Jade (Nephrite & Jadeite) (14:23)

  • Jade is two minerals: nephrite (calcium magnesium silicate) and jadeite (sodium aluminum silicate).
  • Most valued in ancient China as symbol of purity and moral virtue.
  • Major sources: China (nephrite), Myanmar (jadeite).

4. The Tradition of Birthstones

• Origins and History (15:16)
  • Likely stems from Biblical references to Aaron's breastplate (Book of Exodus), later mirrored in zodiac and calendar months.
  • First standardized in 1912 by the National Association of Jewelers (US).
  • "The history of birthstones is a blend of mythology, religion, and cultural tradition dating back thousands of years." — Gary Arndt [15:36]
• Modern List of Birthstones: (16:20)
  • January: Garnet | February: Amethyst | March: Aquamarine | April: Diamond | May: Emerald
  • June: Pearl | July: Ruby | August: Peridot | September: Sapphire | October: Opal
  • November: Topaz | December: Turquoise
  • Lists occasionally amended for commercial or practical reasons.

5. Gemstones in Trade, Diplomacy, and the Modern Era

• Trade Routes (17:11)

  • Gemstones spurred ancient trade (Silk Road), diplomacy, and cultural exchanges.
  • “Gemstones were often gifts between state leaders and played a role in diplomacy and the affirmation of alliances.” — Gary Arndt [17:27]

• Democratization of Gemstones (18:08)

  • Synthetic gemstone creation and new mineral finds have made gems more affordable.
  • “Many gemstones are no longer things for kings and queens, but can be enjoyed by average people as well.” — Gary Arndt [18:22]

Notable Quotes & Memorable Moments

• On classification:

  • "Basically, any mineral or stone that looks pretty can be classified as semi precious if there is a market for it." — Gary Arndt [09:10]

• Personal Anecdote:

  • Opal mining in Coober Pedy: "You just have a field with hundreds and hundreds of holes." — Gary Arndt [11:19]

• On the evolution of value:

  • "Amethyst went from being a precious stone to a semi precious one because large quantities were discovered in Brazil." — Gary Arndt [08:07]

Timestamps for Important Segments

• [03:11] — Introduction to gemstones and classification
• [04:07] — Diamonds
• [04:34] — Rubies
• [06:00] — Sapphires
• [06:53] — Emeralds
• [07:53] — Amethyst and its history
• [09:20] — Semiprecious gems: Turquoise, Opal, Peridot, Aquamarine, Topaz, Lapis Lazuli, Jade
• [15:16] — The tradition and background of birthstones
• [17:11] — Gemstones and ancient trade/diplomatic history
• [18:08] — Modern accessibility and value of gemstones

Conclusion

Gary wraps up by underscoring the enduring allure and democratization of gemstones—from symbols of royal power to affordable tokens of beauty and meaning in modern life. The episode highlights both scientific curiosity and human fascination, weaving together geologic facts, historical anecdotes, cultural significance, and personal travel experiences.