Set gemstones by hand in the manufacture of jewellery items — City & Guilds Limited End-Point Assessment Manufacturing & Engineering Revision
This subtopic covers the essential techniques and principles for securely and aesthetically setting gemstones by hand in jewellery items, including bezel,
Topic Synopsis
This subtopic covers the essential techniques and principles for securely and aesthetically setting gemstones by hand in jewellery items, including bezel, claw, and pave settings. Mastery involves understanding gemstone properties, tool handling, and precise metal manipulation to achieve professional results while minimising risk of damage to stones. Practical application ensures that learners can execute settings that meet industry standards for durability and design integrity.
Key Concepts & Core Principles
- Metallurgy and Alloying: Understanding the properties of precious metals (e.g., caratage, hardness, melting points) and how to create alloys for specific purposes, such as 18ct gold (75% gold, 25% other metals) for durability.
- Fabrication Techniques: Mastery of sawing, filing, soldering, and forming to construct complex jewellery and silverware pieces from sheet metal, wire, and findings.
- Stone Setting: Skills in setting gemstones securely using methods like claw, bezel, pave, and channel setting, ensuring the stone is held firmly without damage.
- Finishing and Polishing: Techniques to achieve a high-quality surface finish, including sanding, polishing with compounds, and applying patinas or plating to enhance appearance and durability.
- Health and Safety: Compliance with COSHH regulations, safe use of tools (e.g., torches, drills), and proper handling of chemicals like acids for pickling and cleaning.
Exam Tips & Revision Strategies
- Practice on a variety of gemstone shapes and hardness levels, as assessors will expect demonstrated competence across different scenarios, not just one type.
- Photograph or document critical stages of your setting process to evidence your understanding of sequential steps and troubleshooting in your portfolio.
- Be prepared to explain the rationale behind your choice of setting style for each gemstone, referencing factors like stone hardness, transparency, and intended wearability.
- For practical assessments, always practice on a test piece with a duplicate stone to refine technique before working on the final assignment piece.
- Document your process with clear notes and photographs to evidence understanding, especially for online portfolio submissions.
- Ensure you reference specific gemstone data (Mohs hardness, refractive index) when discussing setting choices in written components.
- In timed exams, prioritise secure setting over purely decorative flourishes; a well-set stone with clean lines scores higher than an elaborate but flawed attempt.
Common Misconceptions & Mistakes to Avoid
- Applying excessive force when pushing metal over a stone, leading to chipped girdles or cracked gemstones, especially in brittle materials like opal or emerald.
- Neglecting the importance of properly annealed and clean metal, resulting in uneven settings or metal tearing during setting.
- Miscalculating the height or angle of claws or bezels, causing the gemstone to sit too high, tilt, or appear asymmetrical in the final piece.
- Failing to protect gemstones from heat or ultrasonic cleaning damage during post-setting processes such as soldering or cleaning.
- Misjudging the depth of cut when preparing a setting, leading to a loose or unevenly seated stone.
- Applying excessive force with a pusher, causing chipping or cracking of the gemstone, particularly on vulnerable girdles or pointed tips.
Examiner Marking Points
- Award credit for demonstrating correct selection and safe use of setting tools (e.g., pushers, burnishers, gravers) appropriate for the chosen setting style.
- Award credit for accurate preparation of the metal collet or seat to match gemstone dimensions, ensuring a flush fit without gaps.
- Award credit for achieving secure stone setting as evidenced by standard gemstone security tests (e.g., gentle probing with a tool) without movement or rattling.
- Award credit for producing a clean, symmetrical finish with no visible tool marks, scratches, or damage to the gemstone or surrounding metal.
- Award credit for consistently applying appropriate techniques for different gemstone types (e.g., preventing heat from reaching heat-sensitive stones, protecting soft stones).
- Award credit for demonstrating correct identification and handling of gemstone types, considering hardness, cleavage, and heat sensitivity.
- Award credit for accurately executing selected setting styles (e.g., claw, bezel, pave, channel) with secure stone placement and neat finishing.
- Award credit for safely using tools like gravers, pushers, and burrs with proper technique and minimal damage to stone or metal.