Unit of competency Outline
Date retreived
22/07/2026 9:56 PM AWST
22/07/2026 9:56 PM AWST
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Cut and polish opal doublets and triplets
Cut and polish opal doublets and triplets
Unit of competency
National Code
CUVOPA206A
CUVOPA206A
State Code
S7691
S7691
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
70
Description
This unit describes the performance outcomes, skills and knowledge required to cut and polish both opal doublets and triplets.
Notes
Elements and Performance Criteria
1. Prepare to cut an opal doublet or triplet
- 1.1 Identify and obtain consumables required for cutting and polishing an opal doublet or triplet
- 1.2 Select tools and equipment to be used
- 1.3 Determine jewellers’ cutting angle requirements
- 1.4 Dop pre-form on appropriate dop stick using wax or adhesive
2. Cut and polish an opal doublet or triplet
- 2.1 Grind to relevant shape using colour pattern and play as a guide
- 2.2 Grind to shape incorporating jewellers’ side angles, including backing into shape
- 2.3 Dome the top of doublet, leaving a minimum of 1mm above join at side angle
- 2.4 Sand and polish top and sides of opal doublet
- 2.5 Turn stone over and re-dop
- 2.6 Grind, sand and polish backing at jewellers’ angles
- 2.7 Remove stone from dop and clean
3. Cut and polish an opal triplet commercial top
- 3.1 Dop stone on top of triplet top
- 3.2 Grind backing thickness down to approximately 1mm
- 3.3 Grind edge of backing at approximately 30º until the edge of the triplet top is met
- 3.4 Sand and polish backing
- 3.5 Remove stone from dop and clean
4. Cut and polish an opal triplet non-commercial top
- 4.1 Dop pre-form with glass/quartz on top
- 4.2 Shape stone like high domed doublet on grinder
- 4.3 Transform opal colour optically into whole of dome
- 4.4 Sand and polish top and sides of stone
- 4.5 Turn stone over and re-dop on top surface
- 4.6 Grind backing thickness to 1mm
- 4.7 Grind setting edge angle at 30º, until 1mm into top, under- cutting backing
- 4.8 Sand and polish bottom and setting edge and remove any chipping that may occur around edge of top
- 4.9 Remove stone from dop and clean
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.
Consumables may include:
cerium or tin oxide
cleaning spirit
diamond or silicon carbide wheels #220 or #360
diamond polishing compound #2400 to #100000
diamond polishing wheels #3000 to #50000
diamond sanding wheels #280 to #1200
felt or leather buffs
silicon carbide sanding paper #180 to #600.
Equipment may include:
grinding machinery
PPE
polishing machinery
sanding machinery
saw.
Jewellers’ cutting angle requirements may include:
10º to 12º side angle
all sharp edges or acute angles be slightly rounded
flat or domed back
high overall polish and free of defects
sanded or polished back
setting edge to be straight and parallel to back
tolerance for standard millimetre sizes, 0.2mil. + or −.
Wax or adhesives for dopping may include:
any 5 minute adhesive, using aluminium dop sticks
wood glue
hot wax sticks (hot glue gun)
super glues
vacuum dopping
wax (medium to low melting).
Shape may include:
a variety of other shapes
cabochon
dome - high, medium and low
free form
rectangles.
Triplet top materials may include:
clear quartz
commercial standards size triplet tops
glass, plain or plate
lead crystal glass
material of the triplet top should be disclosed
synthetic spinel, corundum and topaz.
Consumables may include:
cerium or tin oxide
cleaning spirit
diamond or silicon carbide wheels #220 or #360
diamond polishing compound #2400 to #100000
diamond polishing wheels #3000 to #50000
diamond sanding wheels #280 to #1200
felt or leather buffs
silicon carbide sanding paper #180 to #600.
Equipment may include:
grinding machinery
PPE
polishing machinery
sanding machinery
saw.
Jewellers’ cutting angle requirements may include:
10º to 12º side angle
all sharp edges or acute angles be slightly rounded
flat or domed back
high overall polish and free of defects
sanded or polished back
setting edge to be straight and parallel to back
tolerance for standard millimetre sizes, 0.2mil. + or −.
Wax or adhesives for dopping may include:
any 5 minute adhesive, using aluminium dop sticks
wood glue
hot wax sticks (hot glue gun)
super glues
vacuum dopping
wax (medium to low melting).
Shape may include:
a variety of other shapes
cabochon
dome - high, medium and low
free form
rectangles.
Triplet top materials may include:
clear quartz
commercial standards size triplet tops
glass, plain or plate
lead crystal glass
material of the triplet top should be disclosed
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:
cut and polish doublets and triplets from a range of types of opal using appropriate consumables and equipment and using commercial and non-commercial triplet tops to accepted industry standards
safely complete the cutting, polishing and cleaning processes, using equipment and consumables safely.
Context of and specific resources for assessment
Assessment must ensure access to an opal-cutting workshop.
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:
cut and polish doublets and triplets from a range of types of opal using appropriate consumables and equipment and using commercial and non-commercial triplet tops to accepted industry standards
safely complete the cutting, polishing and cleaning processes, using equipment and consumables safely.
Context of and specific resources for assessment
Assessment must ensure access to an opal-cutting workshop.
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 |