Evaluating Diamond Quality By Minimising Impurities In Gemstones Training

Objectives:
• Define gemology and its scope in the jewellery industry. • Explain the natural geological processes of diamond formation. • Identify the basic physical and chemical properties of diamonds. • Recognise the importance of quality evaluation in the gem trade.

Topics:
• Overview of gemology as a scientific discipline. • The diamond formation process: mantle conditions and kimberlite pipes. • Basic crystallography and chemical composition of diamond (carbon). • Introduction to the 4Cs of diamond quality. • The role of SAQA and unit standards in skills development.

Objectives:
• Define diamond clarity and its grading scales. • Classify different types of internal inclusions (e.g., crystals, feathers). • Classify different types of surface blemishes. • Understand how inclusions affect light performance.

Topics:
• The concept of clarity as one of the 4Cs. • Detailed study of internal inclusions: crystals, clouds, feathers, pinpoints. • Detailed study of external blemishes: naturals, polish lines, scratches. • Introduction to clarity grading scales (e.g., GIA, CIBJO). • Using a 10x loupe for initial inclusion observation.

Objectives:
• Describe the optical properties critical to diamond beauty. • Explain refraction, dispersion, and brilliance. • Analyse how inclusions interfere with light paths. • Identify the tools used to assess optical performance.

Topics:
• Refractive index and its significance. • Dispersion (fire) and brilliance (brightness). • The concepts of scintillation and contrast. • How inclusions scatter, block, or absorb light. • Introduction to the daylight-equivalent lamp.

Objectives:
• Demonstrate correct posture and lighting for loupe use. • Systematically scan a diamond to map inclusions. • Accurately describe inclusion location using clock positions and zones. • Begin sketching inclusion plots.

Topics:
• Loupe selection, care, and correct holding technique. • The optimal lighting environment for loupe work. • The step-by-step scanning methodology. • The diamond's crown, girdle, and pavilion zones. • Practical session: plotting simple inclusion patterns.

Objectives:
• Set up and calibrate a gemological microscope. • Employ darkfield and brightfield illumination techniques. • Identify inclusions at higher magnifications (20x-40x). • Differentiate between inclusion types using microscopic features.

Topics:
• Parts and functions of a stereo microscope. • Darkfield vs. brightfield illumination: purposes and setup. • Adjusting focus and working distance. • Observing inclusion characteristics at magnification. • Practical: Transitioning from loupe to microscope.

Objectives:
• Identify common crystalline inclusions (e.g., garnet, diopside). • Understand the genesis of mineral inclusions during diamond formation. • Assess the impact of crystalline inclusions on clarity grade. • Distinguish between syngenetic and protogenetic inclusions.

Topics:
• Common mineral guests in diamonds: appearance and identification. • The concept of syngenetic (formed simultaneously) inclusions. • Protogenetic (pre-existing) inclusions. • How size, colour, and relief affect visibility. • Case studies of diamonds with prominent crystal inclusions.

Objectives:
• Classify different fracture types: feathers, cleavages, and breaks. • Evaluate the durability risk posed by different fractures. • Understand how fractures impact clarity and value. • Learn techniques to make fractures less visible during setting.

Topics:
• Feathers: internal fractures, their appearance and causes. • Cleavage planes and their directional weakness. • Assessing fracture depth and potential for propagation. • The impact on grading: 'clarity' vs. 'durability' considerations. • Practical: Identifying and risk-assessing fractures.

Objectives:
• Identify clusters of pinpoints and hazy clouds. • Recognise internal graining and its causes. • Assess when clouds or graining become grade-defining. • Understand the visual effect of these inclusion groups.

Topics:
• Pinpoints: tiny crystals, their clustering and distribution. • Clouds: hazy areas caused by dense pinpoints. • Internal graining: lines or planes from crystal growth distortion. • Differentiating graining from feathers. • Grading exercises focusing on cloudy diamonds.

Objectives:
• Utilise immersion techniques to reduce surface reflections. • Employ fibre-optic lighting for pinpoint illumination. • Master focusing through different depths of a stone. • Document findings with microscope-mounted cameras.

Topics:
• The principle and setup of immersion (using di-iodomethane). • Using fibre-optic lights to highlight specific inclusions. • Techniques for viewing inclusions at the culet or near the table. • Basic digital imaging and annotation for reports. • Practical: Comprehensive inspection of a complex stone.

Objectives:
• Compare major international clarity grading systems (GIA, CIBJO). • Use master stone sets for consistent grading calibration. • Apply the 'six grade rule' for borderline cases. • Grade diamonds to a recognised standard.

Topics:
• In-depth study of GIA and CIBJO clarity scales (Flawless to Included). • The role and use of master comparison diamonds. • Grading criteria: size, nature, number, location, and relief. • Practical grading session using master sets.

Objectives:
• Understand how diamond body colour affects inclusion visibility. • Identify coloured inclusions (e.g., black carbon spots, red garnet). • Assess the combined impact of colour and clarity on appearance. • Recognise 'cape' diamonds and their typical inclusion suites.

Topics:
• The diamond colour scale (D-Z) and fancy colours. • How colour can mask or accentuate inclusions. • Specific inclusion types common in type Ia (cape) diamonds. • Evaluating stones where colour is the dominant characteristic.

Objectives:
• Identify common diamond treatments: fracture filling and laser drilling. • Detect signs of treatment under magnification. • Understand how treatments aim to minimise impurity visibility. • Evaluate the ethical disclosure and value implications of treatments.

Topics:
• Fracture filling: materials used and identifying flash effects. • Laser drilling: identifying drill holes and associated stress fractures. • Other treatments: irradiation, annealing, and coating. • SAQA-aligned ethics: disclosure requirements in South Africa.

Objectives:
• Differentiate between natural, synthetic, and simulant diamonds. • Identify characteristic features of HPHT and CVD synthetic diamonds. • Recognise the inclusion patterns (or lack thereof) in simulants. • Understand the market and regulatory context for synthetics.

Topics:
• Growth structures and metallic flux inclusions in HPHT synthetics. • Strain patterns and graphite inclusions in CVD synthetics. • Common simulants (e.g., CZ, moissanite) and their tell-tale signs. • Regulatory frameworks for disclosure in South Africa.

Objectives:
• Accurately plot all inclusions on a standard diamond diagram. • Use symbols and notations per industry standards. • Create a clarity characteristics plot for a grading report. • Write concise descriptive comments for key inclusions.

Topics:
• Standard diagram formats and symbols for inclusions/blemishes. • Mapping inclusions to precise locations (zone, clock face, distance). • Differentiating between plot symbols for different inclusion types. • Practical: Creating a complete plot from microscope observation.

Objectives:
• Explain how clarity grade directly impacts diamond value. • Use rapaport-style price sheets to estimate value. • Understand the value cliffs between clarity grades. • Assess the marketability of diamonds with specific inclusion types.

Topics:
• The relationship between the 4Cs and price. • Analysing price lists and understanding discounts/premiums. • 'Eye-clean' diamonds and their premium in lower grades. • Case study: Valuing three diamonds with different clarity characteristics.

Objectives:
• Conduct a full clarity assessment on a set of unknown diamonds. • Assign accurate clarity grades using master sets. • Produce professional-grade inclusion plots. • Defend grading decisions based on observed evidence.

Topics:
• Station rotation practical: loupe work, microscope inspection. • Systematic grading of 5 diamonds across the clarity range. • Creating detailed plots for each diamond. • Peer review and facilitator feedback session.

Objectives:
• Identify treated diamonds within a parcel. • Flag potential synthetics or simulants. • Assess durability concerns in diamonds with significant fractures. • Provide a written summary of findings for a hypothetical client.

Topics:
• 'Mystery stone' practical: identifying treatments and synthetics. • Risk assessment for stones with cleavages or large feathers. • Writing a brief technical memo outlining observations and recommendations. • Group discussion on complex cases.

Objectives:
• Implement quality control procedures in a grading environment. • Uphold ethical standards in disclosure and representation. • Understand the legal framework (CPA, NRCS) for gem trading in SA. • Develop a personal code of conduct for gemological practice.

Topics:
• Standard Operating Procedures (SOPs) for consistent grading. • The Consumer Protection Act (CPA) implications for gem dealers. • The role of the National Regulator for Compulsory Specifications (NRCS). • Ethical case studies and dilemma resolution.

Objectives:
• Integrate knowledge of clarity with the other 4Cs (cut, colour, carat). • Review all key concepts from the course. • Practice SAQA-aligned assessment techniques. • Prepare a portfolio of evidence from practical work.

Topics:
• Holistic diamond evaluation: balancing all quality factors. • Review of inclusion identification, grading, and plotting. • Format and expectations of the final summative assessment. • Compiling and organising practical worksheets and plots.

Objectives:
• Demonstrate competence in diamond clarity evaluation under assessment conditions. • Apply ethical reasoning to a practical scenario. • Reflect on personal learning and skill development. • Understand pathways for further professional development.

Topics:
• Written theory test on diamond clarity and impurities. • Practical assessment: grading and plotting of unknown diamonds. • Ethical scenario-based discussion or viva. • Course wrap-up, feedback, and issuing of certificates of attendance.