Cutting – Main Lesson

Unit 9: Cutting Gemstones

What’s This All About? 

From rough rock to sparkling jewel! Jake explains how skilled gem cutters (called lapidaries) transform raw gemstone material into the beautiful finished stones we love.

Key Takeaways: 

• Raw, unfinished gemstone material is called “rough” – this is where “diamond in the rough” comes from 
• Two main cutting styles:
  • Faceted gemstones: Multiple flat surfaces (facets) at precise angles, usually for transparent materials
  • Cabochons: Smooth, domed surfaces without facets, typically for translucent or opaque materials 
• Essential cutting tools:
  • Gem saw for making initial rough cuts and separating material
  • Grinding wheels for shaping the basic form
  • Faceting machines for creating precise angled surfaces
  • Polishing wheels for the final high-gloss finish 
• Critical safety requirements:
  • Protective goggles to shield eyes from debris
  • Heavy-duty gloves to protect hands from sharp edges
  • Respirator or dust mask (some gem dust can be harmful if inhaled)
  • Proper ventilation in work area 
• How cutting affects value:
  • Well-cut gems reflect light perfectly, creating maximum brilliance and sparkle
  • Poor cutting can make even high-quality rough material look dull and lifeless
  • Precision in angles determines how much light returns to the viewer’s eye 
• Important gemstone properties for cutters:
  • Hardness: Affects cutting difficulty and

International Gem Society

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