Application
Those applying the skills and knowledge covered by this unit produce individual pieces that comply with commercial standards and demonstrate the ability to capitalise on the potential of the stone using carving techniques.
Prerequisites
Not applicable.
Elements and Performance Criteria
1. Select the stone and clarify the required outcome | 1.1 Review available pieces of rough opal to determine the suitability or necessity for carving 1.2 Assess the potential of pieces of opal for carving depending on the shape, size, position of the colour, and other characteristics of the stone 1.3 Rub the stone, removing foreign materials and eliminating faults 1.4 Discuss the potential for enhancing stone with colleagues and client 1.5 Determine the approach to be taken to achieve the potential of the stone and maximise the value of the finished product |
2. Select tools, equipment and materials | 2.1 Select carving tools and equipment needed to achieve the desired result 2.2 Select consumables for sanding and polishing the carving 2.3 Determine OHS issues and comply with OHS procedures when using the equipment and consumables |
3. Carve opal | 3.1 Clean the stone, removing foreign materials and eliminating faults 3.2 Grind stone to desired shape using high speed fine grit burr and accommodating existing colour and patterns 3.3 Ensure opal is not heated 3.4 Sand carving with suitable sanding mediums, from coarse to extra fine |
4. Polish the carving | 4.1 Polish entire carving with polishing compound 4.2 Use magnification to check the finished carving for faults and if necessary rectify faults |
5. Ensure that industry standards are satisfied | 5.1 Check the carving to ensure that industry practice and expectations are satisfied 5.2 Correct any faults or defects if required |
Required Skills
Required skills
communication skills to discuss potential for enhancing stone with colleagues and clients
critical thinking and analytical skills to assess the potential of pieces and choose the best approach
planning and organising skills to select appropriate tools, equipment and materials
numeracy skills to use numerical features of machinery
technical skills to:
choose appropriate stone for cutting
cut, sand and polish opals using correct technique
correct faults and defects.
Required knowledge
characteristics of opal gemstone structure
suitability of opal pieces for carving
opal carving process, including required equipment and consumables
safety issues associated with opal cutting and polishing machinery
industry standards for carving.
Evidence Required
The evidence guide provides advice on assessment and must be read in conjunction with the performance criteria, required skills and knowledge, range statement and the Assessment Guidelines for the Training Package.
Overview of assessment | |
Critical aspects for assessment and evidence required to demonstrate competency in this unit | Evidence of the ability to: select opal pieces suitable for carving carve the opal using opal carving equipment to industry standard polish the carving according to industry standards. |
Context of and specific resources for assessment | Assessment must ensure access to: carving and polishing equipment tools and consumables. |
Method of assessment | A range of assessment methods should be used to assess practical skills and knowledge. The following examples are appropriate for this unit: observation of processes and procedures oral and/or written questioning on underpinning knowledge and skills evaluation of finished pieces review of portfolios of evidence review of third-party workplace reports of on-the-job performance by candidate. Assessment methods should closely reflect workplace demands (e.g. literacy) and the needs of particular groups (e.g. people with disabilities, and people who may have literacy or numeracy difficulties, such as speakers of languages other than English, remote communities and those with interrupted schooling). |
Guidance information for assessment | Holistic assessment with other units relevant to the industry sector workplace and job role is recommended. |
Range Statement
The range statement relates to the unit of competency as a whole. It allows for different work environments and situations that may affect performance. Bold italicised wording, if used in the performance criteria, is detailed below. Essential operating conditions that may be present with training and assessment (depending on the work situation, needs of the candidate, accessibility of the item, and local industry and regional contexts) may also be included.
Carving tools may include: | assorted mandrels coarse, medium, fine and extra fine wheels diamond grinding burrs of assorted shapes diamond polishing wheels of assorted shapes diamond sanding wheels of assorted shapes felt polishing buffs sanding discs, assorted grit sizes and diameters silicon carbide grinding burrs of assorted shapes supporting equipment: drip feed watering system dust extraction system wooden polishing buffs. |
Carving equipment may include: | air power tools centre point carvers flexible drive hobby carvers micro motor personal protective equipment (PPE). |
OHS issues for carving may include: | contamination eye protection guarding keeping a clean work area minimising dust inhalation maintaining equipment unattended running machinery. |
Sanding mediums may include: | coarse, medium, fine and extra fine wheels of assorted shapes diamond powders up to #1200 on felt/wooden wheels pumice powders on felt wheels sandpaper wheels and discs up to #1200, assorted sizes silicon carbide powders up to #1200 on felt/wooden wheels. |
Polishing compounds may include: | cerium oxide on felt, leather or wooden wheels or discs diamond compounds from #1200 to #100,000 tin oxide. |
Industry practice and expectations may relate to: | no sharp or protruding areas when shaping, keep the setting into jewellery in mind very high polish no grinding marks or sanding marks on surface no cracks or obvious inclusions that should have been removed with initial grinding avoiding making the carving too large considering how strength of colour may affect the need for detail. |
Sectors
Opal cutting and polishing
Employability Skills
This unit contains employability skills.
Licensing Information
No licensing, legislative, regulatory or certification requirements apply to this unit at the time of endorsement.