Google Links

Follow the links below to find material targeted to the unit's elements, performance criteria, required skills and knowledge

Elements and Performance Criteria

Required Skills

Required skills

planning and organising skills to select and prepare opal backing materials for cutting

problemsolving skills to identify and address common problems associated with precutting processes

numeracy skills to use numerical features of machinery

technical skills to

complete precutting processes for opal doublets and triplets using correct technique and equipment

work safely with opalcutting equipment and materials

Required knowledge

characteristics of opal gemstone structure

processes materials and consumables needed for making doublets and triplets

safety issues associated with opal cutting and polishing machinery

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 appropriate materials for making opal doublets and triplets

complete precutting processes using safe work practices

Context of and specific resources for assessment

Assessment must ensure access to an opalcutting workshop with stones and equipment

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 andor written questioning on underpinning knowledge and skills

evaluation of the final product and other methods as required

review of portfolios of evidence

review of thirdparty workplace reports of onthejob performance by candidate

Assessment methods should closely reflect workplace demands eg literacy and the needs of particular groups eg 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.

Suitable materials may include:	multiple bars of colour with potch between off-cuts from solid production opal from unsuitable boulder iron stone opal prone to crack (triplet only) opalised shell skins thin bar of colour in potch thin seam opal weak colour on a clear base (jelly opal).
General OHS principles and safe operating procedures may include:	complying with the safe operating procedures for each machine good housekeeping using personal protective equipment (PPE) where required.
Appropriate equipment may include:	diamond grinder diamond saw free-hand saw silicon carbide grinder slab saw trim saw.
Backing materials may include:	black jade black potch boulder iron stone clear or transparent potch dark grey potch glass (triplet only) obsidian (black) vitrolite (triplet only).
Blacking agent may include:	black epoxy additives black permanent markers nigrosine.
Adhesive may include:	Loctite UV 358 or 363 (triplet top to opal) UHU Plus 24hr (opal to backing) other glues, such as: UHU Quickset Megapoxy 69 Epoxy 330 Tenax+ super glue Bond 527 Tite On.
Triplet top may include:	clear quartz commercial standards size triplet tops glass, plain or plate lead crystal glass synthetic spinel, corundum and topaz.