Unit of competency Outline
Date retreived
22/07/2026 5:42 AM AWST
22/07/2026 5:42 AM AWST
Whilst all efforts are made to provide accurate and timely information from the relevant source/documentation, please be aware that the information supplied may not be the most current version. The accuracy of the detail has not been confirmed by the Department and therefore should not be relied upon without first confirming the contents.
Complete pre-cutting processes for opal doublets and triplets
Complete pre-cutting processes for opal doublets and triplets
Unit of competency
National Code
CUVOPA205A
CUVOPA205A
State Code
S7690
S7690
TGA Status
Deleted
Deleted
DTWD Status
Deleted
Deleted
State Implementation and Classification
Approved Date
06/11/2014
Field of Education
100307 - Jewellery Making
Original Release Date
06/11/2014
Nominal Hours
25
Description
This unit describes the performance outcomes, skills and knowledge required to select and prepare opal and backing materials for cutting as doublets or triplets and complete all pre-cutting processes.
Notes
Elements and Performance Criteria
1. Select opal for cutting as an opal doublet or triplet
- 1.1 Select suitable materials for cutting as a doublet or triplet based on market requirements and characteristics of the stone
- 1.2 Determine best play of colour and mark that side
- 1.3 Check for flaws with powerful light source and correct if necessary
- 1.4 Follow general OHS principles and safe operating procedures when using machinery for opal cutting
2. Flatten opal and base
- 2.1 Flatten opal on marked side until surface is free of potch and impurities and is completely down to the colour bar using appropriate equipment
- 2.2 Select backing materials and flatten
- 2.3 Lap opal and base until flat satin finish is obtained
- 2.4 Clean and dry opal and base
3. Cement components together
- 3.1 Blacken flattened surface with appropriate blacking agent
- 3.2 Mix adhesive in line with manufacturers’ instructions
- 3.3 Ensure stone is cemented with the best colour face down
- 3.4 Cement flattened surfaces together eliminating excess adhesive and air bubbles
- 3.5 Allow adhesive to harden following manufacturers’ instructions
4. Pre-form opal doublet
- 4.1 Grind stone to expose join between opal and backing
- 4.2 Grind stone to expose best colour
- 4.3 Grind to rough shape
5. Convert doublet to triplet
- 5.1 Manufacture a triplet working with a very thin opal layer
- 5.2 Lap the colour surface of the opal until a thin layer of opal remains on the backing
- 5.3 Clean and dry stone
- 5.4 Cement manufactured triplet top or preferred alternative to the opal surface, eliminating excess adhesive and air bubbles
- 5.5 After curing, grind the stone to expose both joins
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.
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.
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 pre-cutting processes using safe work practices.
Context of and specific resources for assessment
Assessment must ensure access to an opal-cutting 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 and/or written questioning on underpinning knowledge and skills
evaluation of the final product and other methods as required
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.
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 pre-cutting processes using safe work practices.
Context of and specific resources for assessment
Assessment must ensure access to an opal-cutting 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 and/or written questioning on underpinning knowledge and skills
evaluation of the final product and other methods as required
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.
No information
| State Code | National Code | Title | Type |
|---|---|---|---|
| D669 | CUV40611 | Certificate IV in Opal Cutting and Polishing | Qualification |