Facet Nation: A Gemmology Podcast

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Geologist and Crystal Case Studies founder Emily Coulter joins Facet Nation hosts Lucinda and Simon to explain geology from the ground up, connecting Earth’s structure and moving plates to the environments where minerals and gemstones form. Her clear, food-based analogies make core concepts - from rock types to crystallisation - easier to understand, while the hosts bring a gemmology learner’s perspective and practical questions. Geologist Emily explains how magma chemistry, metamorphism and the rock cycle shape the rocks and gemstones we encounter. Simon and Lucinda ask the questions, connect the science to gemmology, and close with Emily’s favourite gems and where to find her.

• Emily Coulter traces her path from studying geology from age 12 to mineral wholesale, jewellery marketing, and founding Crystal Case Studies.
• Geology is the study of Earth and its processes across roughly 4.5 billion years; rocks and minerals preserve clues to that history.
• Minerals have a defined chemistry and ordered crystal structure, while rocks are usually mixtures of minerals; lapis lazuli is a gemstone that is also a rock.
• The hosts and Emily use a peach analogy for Earth’s crust, mantle, and core, and discuss differences between oceanic and continental crust.
• Plate boundaries include divergent, convergent, and transform settings; examples include the Mid-Atlantic Ridge, the Andes, the Himalayas, and the San Andreas Fault.
• Gem formation depends on the right ingredients, heat, pressure, fluids, and time; Emily contrasts metamorphic garnets with opal forming in a sedimentary basin.
• The three rock groups are igneous, sedimentary, and metamorphic; Emily explains how each forms and why metamorphic minerals may align under pressure.
• Intrusive igneous rocks cool underground and can develop larger crystals; extrusive rocks cool at the surface, while magma becomes lava once erupted.
• Igneous chemistry ranges from silica-poor ultramafic and mafic rocks to silica-rich felsic rocks such as granite and rhyolite. Emily compares runny basaltic lava with viscous felsic magma, explaining why felsic eruptions can trap gas and explode.
• Fractional crystallization sorts minerals as magma cools: olivine can form early, while feldspar crystallizes later.
• Pegmatites cool slowly and can contain exceptionally large crystals, as well as concentrated incompatible elements such as lithium and beryllium.
• Emily describes metamorphism as recrystallization without melting, and names garnet, ruby, sapphire, spinel and kyanite among metamorphic gems and minerals.
• Regional metamorphism is associated with mountain-building pressure; contact metamorphism heats surrounding rock, while metasomatism involves chemically active fluids.
• Fluid-driven alteration is important in Colombian emerald formation, where separated ingredients can meet and recrystallize.
• The rock cycle continually recycles material among igneous, sedimentary and metamorphic rocks over geological time.
• Weathering breaks rock down, erosion transports it, and deposition can concentrate dense gems and gold in river gravels.
• Emily shares her interest in unusual amethyst localities, including Jackson Crossroads in Georgia, and her love of garnet varieties.

Takeaways

• Geology, put really, really simply, is the study of Earth and the processes that make up the Earth.
• We're essentially like picking up on the writing of what Earth has left us.
• Minerals, there is like a set definition for a mineral, which is a naturally occurring solid with a defined chemistry and an ordered crystal structure.
• Rocks, on the other hand, are normally mixtures of minerals.
• You want something fiery going on. You want some heat, you want some pressure, you want some fluids.
• The longer that they are in a fluid, the longer that they are able to move around and be mobile and connect with each other and go and hold hands, the bigger the result is.
• Intrusive means below the Earth's surface. Extrusive means above the Earth's surface.
• The moment it gets above the Earth's crust, it is erupted or extruded like toothpaste. It becomes lava.
• The three environments within geology where all rocks form are sedimentary, metamorphic and igneous.
• The more quartz something has, the more viscous it is. The more felsic a rock is, thicker it is.
• They crystallise in sequence and basically are minerals that are able to crystallise at higher temperatures, crystallise first.
• I think of this as all of the elements having time to find their friends.
• They don't like it and they rearrange themselves. They're not melting. It is not melting. It is recrystallisation without melting.
• The key element of metasomatism is the fact that those mineral rich fluids are interacting with the minerals that they're coming into contact with.
• Rocks, like elements within the earth and on the earth are continually being recycled and reused in different ways.
• Weathering, earth processes like wind, rain, ice, weather things down.
• Erosion moves them away from there, like from where they were living before.
• I feel like it's easy for people to not realise necessarily how recycled everything is.
• I love making Gemstone friends with people.

Key Frameworks

• Fractional crystallisation
• The rock cycle
• Regional, contact and fluid-driven metamorphism

Sound Bites

• "I have fear of being involved."
• "They crystallise in sequence"
• "they want to be dropped."

Chapters

00:00
Meet geologist Emily Coulter and hear her path into gems

05:46
A beginner-friendly definition of geology

06:58
What makes a mineral different from a rock

08:55
Granite, basalt, limestone and marble

11:21
Earth’s layers and the peach analogy

14:18
Oceanic and continental crust, plus magnetic stripes

17:57
How moving plates shape Earth’s surface

20:27
Divergent boundaries and new oceanic crust

22:26
Subduction zones, mountain building and transform faults

25:17
Why heat, pressure and fluids matter for gemstones

26:27
The conditions minerals need to crystallize

28:33
Opal’s slow formation in a sedimentary basin

31:06
The three rock types, simply explained

33:10
How pressure gives metamorphic rocks their texture

35:18
Intrusive versus extrusive igneous rocks

38:10
Mafic, ultramafic and felsic chemistry

40:21
How magma changes as it rises through the crust

40:50
Why felsic magma erupts explosively

44:01
Fractional crystallization sorts minerals as magma cools

47:02
Pegmatites, giant crystals and lithium-rich melts

50:47
Metamorphic rocks and Emily’s Scottish garnet story

53:23
Ruby, sapphire, spinel and the challenges of kyanite

55:08
Regional, contact and fluid-driven metamorphism

58:14
How fluids help form Colombian emeralds

01:00:03
The rock cycle: how rocks are recycled

01:02:17
Weathering, erosion and the journey of river gems

01:05:13
Emily’s geology takeaways and favorite gems

01:08:05
Collecting unusual amethyst and different garnets

01:11:17
Where to find Emily and the show’s sign-off

geology basics, rocks and minerals, gemstone formation, tectonic plates, igneous rocks, metamorphic rocks, sedimentary rocks, crystallisation, gemmology, Emily Coulter geology, gemstones, gemmology, fractional crystallisation, pegmatites, metamorphic rocks, rock cycle, volcanic eruptions, garnet, amethyst, gemology

Instagram: @crystalcasestudies

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Lucinda's favourite time of year.

The Spooktacular returns for Halloween 2026.

Join us as we explore the fascinating world of haunted gemstones, ghost stories linked to jewellery, and the mysterious history behind some of the UK's most intriguing ghost tales. Discover the stories, history, and cultural significance of these spectral legends.

The difference between curses and hauntings in gemmology

Historical ghost stories linked to jewellery and gemstones

The story of Lady Ingram's lost pearl necklace and her ghost

The Cheapside Horde and its ghostly apparitions

The legend of the Lady in Red and her lost engagement ring

Queen Elizabeth's pearls and ghostly sightings in Rye

The significance of pearls in ghost stories and folklore

 sound bites

"The Cheapside Horde was buried for 300 years."

"The woman on the fifth floor was called Rose."

"Pearls symbolise purity and religious devotion."

Chapters

00:00 Introduction to Haunted Gemstones and Ghost Stories

01:54 The Difference Between Cursed and Haunted Gemstones

05:05 Lady Ingram's Pearl Necklace and Her Spirit

10:09 The Cheapside Horde and Its Ghostly Encounters

14:56 The Legend of the Lady in Red and the Midsummer's Ring

20:00 Queen Elizabeth's Pearls and Ghostly Sightings in Rye

25:00 The Significance of Pearls in Ghost Lore

29:58 Historical and Cultural Reflections on Haunted Jewellery

haunted gemstones, ghost stories, jewellery history, UK ghost tales, gemmology, paranormal, historical mysteries, spooky stories, ghostly legends, jewellery folklore, uncanny ghost stories, gemology, spooky, halloween, horror, intrigue, mystery

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In part two, we explore the Ugrandite series of garnets, including their chemistry, history, and the stories behind famous varieties like Tsavorite and Demantoid. Join us for a deep dive into gemstone lore, geology, and the vibrant stories that make these stones so captivating.

 key  topics
The isomorphous series of garnets and their chemical formulas
The story of tsavorite's discovery and its geological background
The history and lore of demantoid garnet and its connection to Faberge
The marketing and storytelling aspect of gemstone branding
Different varieties of garnets including grossular, andradite, and uvarovite
The significance of inclusions and their identification in garnets
The story of Campbell Bridges and the discovery of tsavorite in Africa
The cultural and historical significance of garnets in jewelry


 sound bites
"Garnets are part of two isomorphous series."
"Tsavorite was discovered in the 1960s in Zimbabwe."
"Uvarovite is a tiny, beautiful green garnet."


Chapters
00:00 Introduction to Garnets and Episode Overview
01:57 The Isomorphous Series of Garnets Explained
07:56 Discovery and Geology of Tsavorite in Africa
14:56 The Story of Demantoid Garnet and Faberge
28:02 Varieties of Garnets: Grossular, Tsavorite, and More
40:05 The Lore, Inclusions, and Market of Garnets
44:01 The Tragic Tale of Campbell Bridges and Tsavorite

garnets, gemstone lore, tsavorite, demantoid, geology, jewellery, gemstone stories, mineralogy, gemmology, gemology, gems, Tiffany, Campbell Bridges, science

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Arya Akhavan returns! To reveal the secrets he couldn't disclose last time.

Arya has been growing sapphires! And not just any sapphires, every colour of sapphire you can imagine.

A gemologist and scientist, Arya shares groundbreaking insights into synthetic gemstone production, including sapphire growth, colour manipulation, and future innovations. Discover how science and passion are transforming the gem industry and what it means for collectors, faceters and jewellers alike.

Get involved by joining 'The Gemstone Lab' kickstarter here:

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

Groundbreaking sapphire growth techniques
Chemical processes in gemstone creation
The role of computer modeling in gemmology
Market implications of synthetic versus natural gems
Innovations in gemstone colour and treatments
Challenges in sourcing synthetic materials
Future projects in gemstone research
The impact of technology on gem cutting and design


 sound bites
"We want to do this scientifically, rigorously."
"Some synthetics are more rare than natural gems."
"Market perceptions have diverged completely."


Chapters
00:00 Introduction to Arya Akhavan and his work
02:54 Chemical processes in sapphire creation
06:18 Modeling and reverse engineering natural sapphires
08:34 Market trends and consumer preferences for synthetics
12:20 Industrial applications of synthetic gemstones
17:46 Market perception and the future of synthetic gems
22:37 Unique features of synthetic gemstones and market demand
28:43 Market diversification and consumer behavior
34:14 The evolution of synthetic gemstone marketing
43:56 Research and development in gemstone science
50:19 Current progress and future plans for gemstone synthesis
54:07 Closing thoughts and upcoming projects

synthetic gemstones, sapphire growth, gemmology, gemology, gemstone science, lab-grown gems, gemstone colour, gemstone innovation, gem industry, gemstone research, gem cutting, faceting, lapidary, kickstarter, coloured gemstones

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Hello and welcome back to Season 2 of Facet Nation: A Gemmology Podcast

In this episode, we explore the fascinating world of garnets, their varieties, history, and gemmological properties, revealing insights that will deepen your understanding of these captivating gemstones.

key  topics
Garnet varieties and their chemical compositions
Historical significance and trade of garnets
Gemmological properties and identification techniques
The spectrum of garnet colours and their causes
Hybrid garnet varieties and their market value
The importance of locality and deposit sources
Chemical formulas and systems of garnet classification
Inclusions and phenomena in garnet stones
The story behind the names and trade names of garnets


 sound bites
"Most garnets you see are that common brownish red."
"The Ugrandite series has calcium fixed and Y variable."
"Garnet spectrum goes thick, thin, thick, thin."


Chapters
00:00 Introduction to Garnets and Episode Overview
02:01 Common Misconceptions About Garnet Colours
04:08 The Diversity of Garnet Varieties and Their Names
05:32 Historical Trade and Significance of Garnets
07:00 Chemical Foundations of Garnet Classification
09:06 The Pyrope and Almandine Series Explained
11:02 Understanding Garnet Spectra and Colour Variations
12:52 The Rich History of Garnet Use in Jewellery
15:10 The Discovery and Naming of Rhodolite Garnet
17:00 Identifying and Differentiating Garnet Types
18:58 Inclusions, Phenomena, and Cutting Challenges
21:00 Localities and Market Trends for Garnets
23:00 The Fascinating World of Pyrope and Spessartine Garnets
25:08 The Unique Colours and Market Value of Spessartine
26:54 The Story of Malaya Garnet and Its Cultural Significance
29:02 Summary and Final Thoughts on Garnet Diversity

garnets, gemstone varieties, gemmology, almandine, pyrope, spessartine, Ugrandite, gem deposits, gemstone history, bohemian garnets, jewellery, gems, science, learning, education, study

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In this mini episode, Simon shares his summer adventures including gem mining in Oregon, visiting the Spectrum Sunstone Mine, and participating in gemmology events. Lucinda discusses her new gemmology brand, TikTok presence, and recent travels, highlighting the vibrant gem community and upcoming events.

Gem mining in Oregon
Spectrum Sunstone Mine visit
Gemmology events and community outreach
Lucinda's new gemmology brand and TikTok presence
Travel stories and gem history insights

 sound bites
"Met some amazing people in Oregon"
"Spotted a cougar in the wild"
"Check out my new gemmology brand, Cunning Folk"


Chapters
00:00 Introduction and episode overview
02:09 Memorable encounters and wildlife in Oregon
03:00 Exploring Oregon’s history and hot springs
06:58 Meet George, the versatile genius
08:02 Sunstone mining and collecting experiences
09:43 Gem community events and upcoming gatherings
14:34 Lucinda’s gemmology brand and social media launch
15:26 Lucinda’s trip to California and museum highlights
16:18 Lucinda’s UK adventures and historical sites
17:37 Season updates and upcoming episodes

gemmology, Oregon sunstone, gemstone mining, gem events, gem community, TikTok gemmology, Spectrum Sunstone Mine, gem education

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This episode explores the intricate process of diamond manufacturing, from designing and marking to shaping, faceting, and polishing. Hosted by gemmologists Simon and Lucinda, it offers detailed insights into cutting techniques, tools, and the science behind creating stunning gemstones.

End of Season One. THANK YOU FOR LISTENING.

We will be back, enjoy your summer

 key  topics
Diamond designing and marking
Dividing and cleaving methods
Shaping and faceting techniques
Polishing and final finishing
Tools and equipment used in gem cutting

Mastering Diamond Cutting: From Rough to Brilliant
The Art and Science of Gemstone Faceting


 sound bites
"Only diamond can cut a diamond"
"Lasers cut diamonds in twenty minutes"
"Start with the pavilion, then the crown"


Chapters
00:00 Introduction to Gemmology and Diamond Manufacturing
02:35 The Process of Cutting Diamonds
05:13 Dividing and Shaping Diamonds
08:03 Bruting and Faceting Diamonds
10:28 The Role of Technology in Diamond Cutting
13:26 Understanding Diamond Facets and Angles
15:46 Lapidary: The Art of Gemstone Cutting
18:48 Understanding Facet Diagrams
21:24 Dopping Techniques and Adhesives
24:49 The Faceting Process Begins
28:19 Grit Sequence and Polishing
32:31 Cutting the Crown Facets
36:58 Final Steps and Reflections
39:49 Looking Ahead: Future Plans and Wrap-Up

 resources
Gemology Project - Facet Diagrams - https://gemologyproject.com
Ultratech Gem Faceting Machines - https://ultratec.com
Andrew Ian Brown's Gemstone Design Books - https://www.amazon.com/s?k=Andrew+Ian+Brown+gemstone+design


Instagram - https://instagram.com/gemmology_si

diamond manufacturing, gemmology, faceting, cutting techniques, gemstone design, diamond polishing, gemmology course, gemstone tools, gemmology education

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In this episode, Lucinda and Simon explore the fascinating world of gemstone cutting and fashioning, covering essential terminology, techniques, and historical insights crucial for gemologists and enthusiasts alike.

 key  topics
Gemstone cutting terminology
Differences between lapidary and diamond manufacturing
Factors influencing gemstone cut decisions
Historical gem cutting techniques and innovations
Practical tips for evaluating rough stones

Gem Cutting Vocabulary
Diamond Manufacturing Process
Gemstone Cut Optimization

Review gemstone terminology regularly
Practice evaluating rough stones before cutting
Explore historical gem cutting techniques


Titles
Mastering Gemstone Cutting: Techniques, History, and Industry Insights
The Art and Science of Gem Cutting: A Comprehensive Guide


 sound bites
"The old mine cut has a rich history."
"Inlays and carvings add artistic value."
"A break in gem cutting is coming soon."


Chapters
00:00 Introduction to Gemmology and Cutting Gemstones
03:01 The Importance of Understanding Gemstone Cuts
05:43 Insights from Gem Cutting Experts
08:26 The Process of Fashioning Gemstones
11:09 Types of Gemstone Fashioning
13:58 Evaluating Rough Gemstones
16:37 Key Factors in Gemstone Cutting
19:13 Understanding Diamond Manufacture
21:58 Historical Perspectives on Gem Cutting
24:42 Modern Trends in Gem Cutting
27:24 Conclusion and Future of Gem Cutting
29:12 Understanding Diamond Cuts and Their History
32:29 The Anatomy of a Diamond: Key Features
34:51 Exploring Brilliant Cut Stones
36:42 Step Cuts vs. Brilliant Cuts: A Comparison
38:04 The Evolution of Rose Cuts and Mixed Cuts
40:32 Fantasy Cuts: The Art of Gemstone Cutting
41:35 Cabochons: The Gateway to Gem Cutting
44:25 Beads, Cameos, and Intaglios: Decorative Techniques
46:10 Carvings, Inlays, and Mosaics: Artistic Expressions

The V&A Museum Gem Collection - https://www.vam.ac.uk/collections/gems
UK Facet Cutters Guild - https://ukfcg.org/


 guest links
Instagram - https://instagram.com/facetnationgemmology
Email - mailto:[email protected]

gemmology, gemstone cutting, gem fashioning, gemmology exam, gem cutter, gemstone shapes, diamond manufacturing, gemmology history, gemstone grading, jewellery industry

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Join Lucinda, Simon, and Michelle Mai as they explore the art and science of precision gem cutting. Discover techniques, tools, design principles, and the inspiring journey of a master gem cutter in this engaging episode.

Precision gem cutting techniques
Tools and machinery for faceting
Design principles for gemstones
Materials used in gem cutting
The journey of a gem cutter


Guest  name
Michelle Mai


Titles
Mastering Precision Gem Cutting: Techniques and Inspiration
The Art and Science of Gem Faceting with Michelle Mai


 sound bites
"Equipment is a huge barrier to entry"
"Polishing quartz is challenging for me"
"Start with cabochons to learn the basics"


Chapters
00:00 Introduction to Precision Gem Cutting
08:09 Michelle's Journey into Gem Cutting
10:53 Understanding Gem Cutting Machinery
13:09 The Learning Curve in Gem Cutting
15:57 Design Principles in Gem Cutting
18:57 Challenges with Different Gem Materials
21:36 Creating Unique Gem Designs
24:36 The Role of Light in Gem Performance
27:00 Inspiration Behind Michelle's Designs
29:59 Favorite Designs and Techniques
32:31 Conclusion and Future Aspirations
35:41 Exploring Favourite Materials in Gem Cutting
37:53 Natural vs. Synthetic Gemstones: A Balanced Perspective
39:48 Navigating Risk and Responsibility in Gem Cutting
44:08 Advice for Aspiring Gem Cutters
51:04 Encouragement for Beginners in Lapidary Arts

 resources
Amateur Gemstone Faceting Volume One by Tom Herbst - https://www.amazon.com/dp/B07V4V7V4X
UK Facet Cutters Guild - https://www.ukfcg.org/
Gem Cut Studio - https://gemcutstudio.com/
Reddit r/shinypreciousgems - https://www.reddit.com/r/shinypreciousgems/


 guest links
Reddit - https://www.reddit.com/user/MichelleMai
Instagram - https://www.instagram.com/michellemai/

gem cutting, gemmology, precision faceting, gemstone design, gem tools, gemstone materials, gem industry, gem education

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In this episode of FacetNation, Simon and Lucinda delve into the fascinating world of tourmaline, particularly focusing on its significance in San Diego's gemstone history and the impact of the Dowager Empress Cixi on the pink tourmaline market. They explore the rise and fall of the tourmaline industry, the unique characteristics of the stone, and the methods used to identify it. The conversation is rich with historical anecdotes and insights into the gemmology field, making it an engaging listen for enthusiasts and newcomers alike. Also in this episode, Lucinda and Simon delve into the fascinating world of tourmaline, exploring its color variations, treatments, and the rise of Paraiba tourmaline as a highly sought-after gemstone. They discuss the geological origins of Paraiba tourmaline, its global appeal, and highlight famous examples, including the Ethereal Carolina Divine Paraiba. The episode concludes with a look at the stunning Liddicoat tourmaline slice, showcasing the beauty and complexity of this remarkable gemstone.


Tourmaline is a significant gemstone with various types.
San Diego has a rich history of gemstone mining.
The Dowager Empress Cixi played a crucial role in popularising pink tourmaline.
Zixi's love for pink tourmaline influenced the gemstone market.
The decline of the tourmaline market followed Cixi's death.
Testing tourmaline requires specific techniques due to its colour variations.
Tourmaline can be mistaken for other gemstones.
Historical context enhances the value of gemstones.
Gemstones often have fascinating stories behind them.
Understanding gemstone history can enrich appreciation for them. Some stones show two completely different colours.
Watermelon tourmalines need both pleochroic responses listed.
Tourmaline can be treated to enhance colour.
Paraiba tourmaline is the most valuable type.
The discovery of Paraiba tourmaline changed the market.
Paraiba tourmaline's price skyrocketed due to rarity.
Geological events created the conditions for tourmaline formation.
Nigerian and Mozambican tourmalines are similar to Brazilian Paraiba.
Famous tourmalines often have historical significance.
The Liddicoat tourmaline slice is a stunning example of tourmaline beauty.

The Allure of Tourmaline: A Gemstone Journey
Unveiling San Diego's Gemstone Secrets
The Legacy of the Dowager Empress Cixi
Tourmaline: From Mine to Market


"She banned foot binding."
"It's a serious bottleneck."
"It's called Heitorita."
"It looks like stained glass."


Chapters
00:00 Introduction to Tourmaline Part Two
02:30 Exploring San Diego's Gemstone History
05:57 The Dowager Empress Cixi and Pink Tourmaline
17:20 The Decline of the Tourmaline Market
18:22 Testing Tourmaline: Identification Techniques
22:01 Understanding Tourmaline's Colour Variations
25:01 The Treatment and Enhancement of Tourmaline
26:17 The Discovery of Paraiba Tourmaline
30:39 The Rise of Paraiba Tourmaline's Value
34:00 Geological Origins of Paraiba Tourmaline
38:25 The Global Appeal of Paraiba Tourmaline
39:05 Famous Paraiba Tourmalines and Their Significance
42:30 The Liddicoat Tourmaline Slice and Its Beauty

tourmaline, gemstones, San Diego, Dowager Empress Cixi, gemmology, pink tourmaline, gemstone testing, history, gem market, California tourmaline, Paraiba tourmaline, gemstone treatment, colour variations, gemmology, gemstone value, geological origins, famous gemstones, Liddicoat tourmaline

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