Episodios

  • 18. The Best Kept Secrets of Spinel
    Jan 5 2026

    Send us a text

    Summary

    In this episode, Lucinda and Simon explore the fascinating world of spinel, a gemstone often overshadowed by rubies and sapphires. They discuss its chemical composition, colour variations, and historical significance, as well as the modern rise of synthetic spinel. The conversation delves into the properties that make spinel a desirable choice for jewellery, its unique inclusions, and the testing methods used to identify it. The hosts also highlight famous spinels throughout history, emphasising the gemstone's newfound recognition and value in the gemological community.

    Takeaways

    Spinel is often confused with rubies and sapphires due to its similar appearance.

    The chemical composition of spinel is magnesium aluminum oxide.
    Spinel comes in a variety of colors, including red, blue, and black.

    Spinel is a durable gemstone, making it suitable for everyday wear.

    Historically, spinel was often misidentified as ruby, leading to its nickname 'balast ruby.'

    The Mahenge region of Tanzania produces some of the most valuable spinels.

    Spinel crystals can form in octahedral shapes, similar to diamonds.

    Synthetic spinel is produced using the Van Gogh flame fusion method.

    Testing spinel involves using a refractometer to determine its refractive index.
    Famous spinels include the Black Prince's Ruby and the Timer Ruby.

    Chapters

    00:00 New Year, New Beginnings
    02:07 The Allure of Spinel
    03:47 Understanding Spinel's Composition
    07:59 The Color Spectrum of Spinel
    10:55 Spinel Crystals and Their Formation
    14:08 Historical Significance and Modern Sources
    17:59 Inclusions and Unique Features of Spinel
    18:58 Identifying Spinel vs. Other Stones
    24:06 Synthetic Spinel: The Modern Challenge
    30:11 Introduction to Spinels and Spectroscopy
    34:03 Understanding Spinel Spectra
    35:40 Famous Spinels: The Black Prince's Ruby
    38:06 The Historical Significance of Spinels
    41:29 The Sumerian Spinel: Myths and Legends
    44:32 The Cote de Bretagne Spinel: A Unique Jewel
    47:10 The Modern Recognition of Spinels

    Más Menos
    43 m
  • 17. Interview: Rosie Young. Lab Gemmology and all things Sunstone
    Dec 22 2025

    Send us a text

    In this episode of Facet Nation, hosts Simon and Lucinda chat with Rosie Young, a lab gemologist at GCS Lab. Rosie shares her journey from a tax advisor to a passionate gemmologist, discussing her education, experiences, and the day-to-day operations in a gem lab. The conversation delves into the fascinating world of sunstones, including their unique properties, treatments, and the science behind their colours. Rosie also highlights her research on sunstones and the importance of spreading awareness about this beautiful gemstone. The episode concludes with insights into the gem market and the joy of discovering new gemstones.


    Takeaways

    Rosie transitioned from tax advising to gemmology, pursuing her passion.

    She graduated with a BSc in Gemmology and started working at GCS Lab.

    Lab gemmology involves analysing gemstones using advanced equipment.

    Sunstones are a unique and under-appreciated gemstone.

    Copper-bearing sunstones come primarily from Oregon.

    Diffusion treatment can alter the appearance of gemstones.

    Color zoning in sunstones is a fascinating phenomenon.

    Rosie enjoys sharing her knowledge about gemstones with others.

    The gem market is constantly evolving with new trends.

    Sunstones have a variety of localities and unique characteristics.


    Titles

    Exploring the World of Gemmology with Rosie Young

    The Journey from Tax Advisor to Gemmologist


    Sound Bites

    "I always loved gems as a kid."

    "It's worked out really well for me."

    "I would just be happy for it."


    Chapters

    00:00 Introduction to Gemmology and Guest Introduction

    04:39 Rosie's Journey into Gemmology

    07:06 Educational Experiences in Gemmology

    09:43 Internship at GIA and Research Focus

    12:19 Working at GCS Lab: Daily Operations

    15:11 Lab Equipment and Techniques

    17:33 Trends in Gemstone Submissions

    20:18 Favourite Gemstones and Unique Finds

    22:46 Research on Sunstones and Their Varieties

    26:14 The Quest for Sunstone Knowledge

    27:18 Origins of Sunstones

    28:25 Locality Preferences and Unique Characteristics

    28:59 Copper-Bearing Sunstones: A Comparative Analysis

    30:48 Colour Zoning in Oregon Sunstone

    33:29 Copper Diffusion Experiments

    36:29 The Science Behind Diffusion Treatments

    38:15 Identifying Diffusion-Treated Stones

    42:23 Personal Connections to Sunstone

    44:59 Exploring the World of Sunstones

    47:34 Inspiration from Gemstones

    48:25 Holiday Greetings and Future Plans


    Keywords


    gemmology, sunstone, lab gemmology, gemstone treatments, GCS Lab, Rosie Young, gem education, gemstone analysis, gem certification, gem market trends

    Más Menos
    50 m
  • 16. Light & Gem Testing Instruments: The Polariscope
    Dec 15 2025

    Send us a text

    In this episode of Facet Nation, Simon and Lucinda explore the intricacies of gemmology, focusing on the polariscope and its significance in testing gemstones. They discuss the behaviour of light in relation to isotropic and anisotropic materials, the importance of understanding internal stress in gems, and the use of the conoscope for identifying gemstones. The conversation emphasises community engagement and the joy of learning in the field of gemmology.



    Titles

    The Fascinating World of Gemmology

    Understanding Gem Testing Instruments


    Sound bites

    "We want to see more cats."

    "Light needs to be able to get through."

    "The bullseye is diagnostic of quartz."



    Chapters

    00:00 Introduction to Gemmology and Light Testing

    02:55 Deep Dive into the Polariscope

    05:26 Understanding Polarisation and Light Behaviour

    08:01 Isotropic vs. Anisotropic Materials

    10:41 Testing Gemstones with the Polariscope

    13:05 Vibration Directions in Gemstones

    15:49 Birefringence and Optical Axes

    18:41 Conclusion and Key Takeaways

    23:52 Understanding Polycrystalline Materials

    27:19 Exploring Strain and Anomalous Double Refraction

    30:39 Identifying Tabby Extinction and Writhing Snakes

    34:11 The Role of the Conoscope in Gem Testing

    37:26 Interference Figures: The Bullseye and Beyond

    39:47 Biaxial Interference Figures and Their Significance



    Understanding the importance of the polariscope in gemmology.

    Light behaviour is crucial for interpreting gemstone properties.

    Isotropic materials remain dark under polarised light.

    Anisotropic materials show varying light responses.

    Polycrystalline materials allow light through in multiple directions.

    Anomalous double refraction indicates internal stress in gemstones.

    Conoscopes help identify gemstone types through interference figures.

    Interference figures provide diagnostic information about gemstones.

    Recognising tabby extinction and writhing snakes in gem testing.

    The podcast emphasises community engagement and learning.


    gemmology, polariscope, isotropic, anisotropic, gemstones, light behaviour, gem testing, interference figures, conoscope, anomalous double refraction, gemology

    Más Menos
    46 m
  • 15. Live Episode - Tanzanite - The Gem and Mineral Show London
    Dec 8 2025

    Send us a text

    In this live episode of Facet nation, hosts Simon and Lucinda share their experiences at the London Gem and Mineral Show, where they discuss the fascinating gemstone Tanzanite, its properties, discovery, and significance as a birthstone for December. They delve into the science behind Tanzanite's colour, its varieties, and its cultural importance, while also sharing personal anecdotes and insights from their gemmology journey.


    The London Gem and Mineral Show was a significant experience for the hosts.

    Tanzanite is the birthstone for December, making it a popular gift choice.

    Zoisite is the mineral family that Tanzanite belongs to.

    Tanzanite's colour is influenced by the presence of vanadium and iron.

    The discovery of Tanzanite is attributed to various individuals, leading to some controversy.

    Tanzanite requires heat treatment to achieve its vibrant blue colour.

    The gemstone is known for its vitreous lustre and unique trichroism.

    Tanzanite is relatively soft, making it less suitable for certain types of jewellery.

    The largest faceted Tanzanite weighs 703 carats, showcasing its potential size.

    Tanzanite is associated with transformation and spirituality in various cultures.



    Titles

    The Fascinating World of Tanzanite

    Tanzanite: A December Birthstone Exploration


    Sound bites

    "It's our first ever live show!"

    "Tanzanite has a vitreous luster."

    "Tanzanite is a very rare stone."


    Chapters


    00:00 Introduction to the Live Show Experience

    03:16 Exploring Tanzanite: The Birthstone of December

    06:19 Understanding Zoisite and Its Varieties

    09:08 The Science Behind Tanzanite's Colour and Properties

    12:25 The Discovery and Commercialisation of Tanzanite

    15:11 Tanzanite's Unique Characteristics and Uses

    18:09 Metaphysical Properties and Cultural Significance of Tanzanite

    21:12 Conclusion and Future of Facet nation Podcast


    Tanzanite, Gemmology, Birthstone, Zoisite, Live Podcast, Gemstones, Mineral Show, Colour Properties, Discovery, Metaphysical Properties, Gemology, Tiffany, Trichroism

    Más Menos
    28 m
  • 14. Light and Optics in Gemstones
    Dec 1 2025

    Send us a text

    In this episode of the Facet nation podcast, Simon and Lucinda delve into the intricate world of light and optics as they relate to gemmology. They explore the fundamental properties of light, including reflection and refraction, and discuss how these principles apply to gemstones. The conversation covers the importance of cut in diamonds, the various optical effects seen in gemstones, and the significance of birefringence. The hosts also touch on the practical applications of these concepts in gem testing, providing listeners with a comprehensive understanding of how light interacts with gemstones.


    Takeaways

    Light is a form of electromagnetic energy that travels at high speeds.
    Visible light is a small part of the electromagnetic spectrum, detectable by the human eye.
    Brilliance in diamonds is a result of precise cutting and internal reflections.
    The cut of a diamond significantly affects its appearance and brilliance.
    Total internal reflection is crucial for maximizing light return in gemstones.
    Aventurescence is caused by reflective inclusions within a gemstone.
    The cat's eye effect requires specific needle-like inclusions to be visible.
    Asterism is a star-like effect that requires multiple sets of inclusions.
    Understanding birefringence helps in identifying different gemstone types.
    The optical properties of gemstones are essential for gem testing and identification.

    The Fascinating World of Gemology
    Light and Optics: A Gemologist's Guide

    Sound bites
    "Light is a form of electromagnetic energy."
    "Visible light is white."
    "Brilliance is what makes diamonds special."


    Chapters

    00:00 Introduction to Facet nation and Light in Gemmology
    03:38 Understanding Light and Its Properties
    09:14 Refraction and Its Importance in Gemmology
    17:39 Single vs. Double Refraction in Gemstones
    23:52 Birefringence and Its Applications in Gem Testing
    24:41 Understanding Light and Gemstones
    28:24 The Brilliance of Diamonds
    31:49 The Importance of Cut in Diamonds
    34:22 Exploring Fire and Dispersion in Gemstones
    37:05 Optical Effects in Gemstones
    46:15 Chatoyancy and Asterism: The Star Effect
    49:08 Labradoressence and Other Optical Phenomena

    gemology, light, optics, reflection, refraction, birefringence, diamonds, optical effects, gemstones, gem testing, gemmology

    Más Menos
    52 m
  • 13. Interview: Video Game Gemstones and Precision Gem cutting with Arya Akhavan
    Nov 24 2025

    Send us a text

    In this episode Lucinda and Simon speak to gem cutting pioneer Arya Akhavan, his trademarked gemstone cuts; the Void Reaver and the Legend of Zelda inspired Rupee cut are some of the most beautiful you'll ever see.

    Listen to this fascinating interview full of almost revealed secrets and future excitement. If you love gems, videogames or videogame gems, this is the interview for you.


    Arya Akhavan is a pioneer in video game-themed gem cutting.

    The gem cutting community is becoming more collaborative and innovative.

    Video games have a historical connection to gemstones as valuable items.

    Creating video game-inspired gems involves both artistic and technical skills.

    The rupee cut is a unique design that poses specific challenges.

    Community forums like Shiny Precious Gems foster support and creativity.

    Modern gem cutting techniques are evolving rapidly, especially post-COVID.

    There is a growing demand for high-end video game-themed jewelry.

    Education in gem cutting is becoming more accessible and innovative.

    The emotional connection to gemstones influences how they are valued and cherished.


    Link:

    Kickstarter

    https://www.kickstarter.com/projects/canadacrystallabs/the-gemstone-lab-growing-never-before-seen-lab-sapphires

    Reddit

    https://www.reddit.com/r/Shinypreciousgems/


    Titles

    Gemology Meets Gaming: The Rupee Cut Revolution

    Crafting Gems: Arya Akhavan's Journey


    Sound bites

    "It's a really fascinating chat."

    "Nobody else had published them."

    "It's a rescue puppy."


    Chapters

    00:00 The Emergence of Video Game Jewelry

    04:56 Educational Challenges in Gem Cutting

    07:36 The Growth of Modern Gem Cutters

    10:19 Community Building in Gemology

    13:20 The Intersection of Gemstones and Video Games

    15:52 Creating the Rupee Cut

    18:38 Characteristics of the Rupee Cut

    21:40 Materials for Gem Cutting

    24:11 Challenges with Certain Gem Materials

    25:12 Setting and Wearing Gemstones

    26:59 Emotional Connections to Cut Stones

    28:27 Innovative Gemstone Designs

    29:48 The Evolution of Gem Cutting Techniques

    33:09 The Renaissance of Modern Gem Cutting

    36:26 Future Innovations in Gemstone Research

    43:01 Exploring Corundum and Sapphires

    45:18 Community Engagement in Gemology

    46:47 The Value of Rupees and Gaming References


    gemmology, video game gems, gem cutting, Arya Akhavan, gemstone design, community building, gem education, rupee cut, innovative designs, gem materials, gemology


    Más Menos
    47 m
  • 12. Light and Wave Theory - A History
    Nov 17 2025

    Send us a text

    In this episode of the Facet Nation: A gemmology podcast, hosts Lucinda and Simon explore the intricate relationship between light and gemstones. They discuss the importance of light in visibility and gem testing, delve into the characteristics of light waves, and examine historical theories of light, including Newton's corpuscular theory and Huygens' wave theory. The conversation also covers the significance of polarised light, the behaviours of light such as reflection, refraction, and diffraction, and the implications of the double slit experiment. The episode concludes with a look ahead to future topics related to light and gemmology.


    Titles

    Exploring the Nature of Light in Gemmology

    The Journey of Light: From Waves to Gems


    Sound bites

    "What is light?"

    "Light is essential for visibility."

    "Polarised light reduces glare."



    Chapters

    00:00 Introduction and Graduation Celebration

    03:03 Mnemonic for Mohs Scale

    05:48 Understanding Light and Optics

    11:28 Characteristics of Waves

    16:59 Polarised Light and Its Applications

    22:21 Wave Behaviours: Reflection, Refraction, and Diffraction

    24:16 History of Light Theory and Newton's Contributions

    26:29 Theories of Light: Newton vs. Huygens

    30:07 The Double Slit Experiment: Proving Wave Theory

    33:57 Einstein and the Birth of Modern Physics

    36:10 The Photoelectric Effect: Light as Particles

    38:31 Understanding Light: Refraction and Colour

    42:09 Reflection, Transmission, and Absorption of Light

    43:50 Recap and Future Discussions on Light and Gemmology



    Takeaways

    Light is essential for visibility and understanding gemstones.

    The Mohs scale mnemonic can be improved for better memorization.

    Light behaves as both a wave and a particle, known as wave-particle duality.

    Polarised light is crucial for reducing glare and enhancing visibility.

    Understanding wave characteristics like amplitude and frequency is vital for gemmology.

    Reflection, refraction, and diffraction are key behaviours of light waves.

    Historical theories of light evolved from Newton's corpuscular theory to wave theories.

    The double slit experiment demonstrated light's wave nature through interference patterns.

    Light interacts with matter, affecting colour perception and gemstone identification.

    Future discussions will delve deeper into light's role in gem testing.


    gemmology, light, optics, waves, Mohs scale, polarised light, reflection, refraction, diffraction, history of light, gemology, science

    Más Menos
    47 m
  • 11. Gem weight and Specific Gravity: How heavy are your gemstones?
    Nov 10 2025

    Send us a text

    In this episode of the Facet nation podcast, Simon and Lucinda delve into the intricate world of gemmology, focusing on the concepts of weight, density, and specific gravity. They explore the historical significance of Archimedes' principle, practical methods for hydrostatic weighing, and the use of heavy liquids in gem identification. The hosts engage with their audience, sharing insights and personal anecdotes, while emphasising the importance of these concepts in the gem trade.


    Titles

    The Weight of Gems: Understanding Density and Gravity

    Gemmology 101: Weight, Density, and Specific Gravity



    Sound bites


    "Weight is crucial in gem pricing."

    "The importance of weight in gem pricing."

    "Carat weight affects the price per carat."



    Chapters

    00:00 Introduction and Welcome

    02:53 Engagement with Listeners

    05:14 Understanding Weight and Density in Gemstones

    10:33 The Importance of Carat Weight

    14:49 Price Per Carat and Market Dynamics

    20:18 Specific Gravity Explained

    25:11 Historical Context of Specific Gravity Measurement

    27:24 Eureka! The Principle of Displacement

    28:39 Hydrostatic Weighing: The Science of Density

    33:45 Heavy Liquids: Testing Gemstones at Home

    38:17 The Game of Sink, Swim or Suspend


    Weight is crucial in gem pricing and identification.

    Specific gravity is a key property for gemologists.

    Archimedes' principle is foundational in understanding density.

    Hydrostatic weighing is a practical method for determining specific gravity.

    Heavy liquids can help distinguish between different gemstones.

    Amber's specific gravity allows it to float in saltwater solutions.

    Carat weight affects the price per carat of gemstones.

    Understanding heft can aid in gem identification.

    Gemmologists often use digital scales for precise measurements.

    Engagement with listeners enhances the podcast experience.


    gemmology, weight, density, specific gravity, gemstones, Archimedes, hydrostatic weighing, heavy liquids, carat weight, gem identification, gemology

    Más Menos
    51 m
adbl_web_global_use_to_activate_DT_webcro_1694_expandible_banner_T1