Inclusions in gemstones:Gems in Gems

Egor GavrilenkoInstituto Gemológico Español

Inclusions in gemstones:Gems in Gems

• Introduction• Types of inclusions• Importance of inclusions:

In Geology In Gemology

• Methods of inclusion’s studies• The artistic side of inclusions:

Photomicrography Special cuts and jewelry

Introduction

• Inclusions: Particles of other minerals or cavities found inside crystals, trapped during crystal’s growth or formed inside after the host mineral formation.

• In gemology, are also considered mechanical inclusions (fissures, growth lines, etc.) and color zoning, described together as “internal characteristics” of gems.

Introduction• Negative impact on quality of gemstones (Clarity)

Photos Anthony Cáceres

Types of inclusions: By type of trapped material

• Single phase: Solid Liquid Gaseous

• Two phases: Liquid-vapor Liquid-liquid Liquid-solid Solid-gaseous

• Three phases…

• Multiphase …. Photo Juan S. Cózar

Types of inclusions: By time of their formation

• For solid inclusions Protogenetic Syngenetic Epigenetic

• For fluid inclusions Primary Secondary Pseudo-secondary

Applications in Geology

• Sequence of mineral formation in mineral deposits

• P-T conditions of mineral formation (fluid inclusions study, thermodynamic stability diagrams for syngenetic minerals)

• Development of genetic models for mineral deposits (mineralization fluids origin, age, relation with magmatic and tectonic events, etc.).

Importance for Gemology

• Aesthetic importance • Importance for gem’s identification• Special collections

Photo Marco Campos Venuti

Photo Marco Campos Venuti

Importance for Gemology

• Aesthetic importance: Color of some gems Special phenomena:

• Aventurescence• Chatoyancy• Asterism

Special gemological varieties

Importance for Gemology

• Importance for gem identification: Type of gem Natural or synthetic Treatments Geographic origin

Photo Juan S. CózarPhoto José María AlonsoPhoto José María Alonso

Methods of inclusions studies

• Microscopic observation + photomicrography• Electron microscopy + EDX or WDX (punctual)• X-ray Fluorescence Spectroscopy (global)• Raman Spectroscopy (punctual or global)• FTIR Spectroscopy (punctual or global)• Fluid inclusions microthermometry

Methods of inclusions studies

• Microscopic observation + photomicrography• Electron microscopy + EDX or WDX (punctual)• X-ray Fluorescence Spectroscopy (global)• Raman Spectroscopy (punctual or global)• FTIR Spectroscopy (punctual or global)• Fluid inclusions microthermometry

Fluid inclusions microthermometry

Emeralds from the Urals

H2Oliq - 70-80 vol %CO2liq ~ 5-7 vol % Vapor - 25-30 vol %

TmCO2= -56.6-57.2Tmice= -3.8-6.8Tmclatr= 6.2-9.4

Th(LV)CO2= 16-29

Th(VL)liq 250-330

T = 350-450 oC, P = 2,5-3 kb,8 wt % NaCl

The artistic side of inclusions

• Photomicrography• Special cut gems to highlight

the beauty of inclusions• Designer jewelry focused on

gems with inclusions

Special cut gems

Richard P. Homer, Gems by Design, Inc., Kent, OH, USA30.95 ct. rutilated Quartz with a single natural needle in the center.

AGTA Spectrum Awards Winners 2012Honorable Mention, Innovative Faceting

John Bailey, www.gemstoneartist.com“The Sword In the Stone” - quartz with single brookite inclusion

John Bailey, www.gemstoneartist.comOregon Sunstone using copper schiller to highlight concave faceting

John Bailey, www.gemstoneartist.comRed Hematite flake in Quartz. Flake oriented to give color to the gem.

John Bailey, www.gemstoneartist.comQuartz with phantom planes oriented to reflect

as "angel wings"

Gold neclace with rutilated quartz, by Xisco Clapés Triviño

Custom made jewelry

Pendant with rutilated quartz in white gold, by Laura Márquez

White gold pendant with quartz with epidote inclusions and green tourmalines, by Laura Márquez

White gold pendant with rutilated quartz and citrines, by Laura Márquez

Quartz with tourmaline needles, cut by Munsteiner, white gold pendant by Laura Márquez

- Thanks for your attention -