CUVOPA401A
Use opal carving tools

This unit describes the performance outcomes, skills and knowledge required to carve opal, including all the processes from the selection of the piece of opal to the completed polished carving.

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.