Unit of competency Outline
Date retreived
22/07/2026 1:10 AM AWST
22/07/2026 1:10 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.
Cut and polish solid opals
Cut and polish solid opals
Unit of competency
National Code
CUVOPA204A
CUVOPA204A
State Code
S7689
S7689
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 a solid opal to make a finished cabochon or other shape from a pre-formed stone.
Notes
Elements and Performance Criteria
1. Prepare to cut an opal solid
- 1.1 Identify and obtain consumables required for cutting an opal solid
- 1.2 Select tools and equipment to be used
- 1.3 Determine jewellers’ cuttingangle requirements
- 1.4 Dop pre-form on appropriate dop stick using wax or adhesive as appropriate
- 1.5 Follow general OHS principles and safe operating procedures when using tools, equipment, machinery and consumables for opal cutting
2. Cut and polish top surface of opal
- 2.1 Fine grind shape and dome ensuring continuity of contour and maintaining jewellers’ setting angles
- 2.2 Sand opal to remove grinding marks using appropriate sanding papers or diamond wheel
- 2.3 Polish top surface of opal with polishing compound to a high lustre
3. Cut and polish back surface of opal
- 3.1 Remove stone from dop, turn over and replace on dop checking alignment
- 3.2 Grind the back of the stone to jewellers’ standards maintaining continuity of form and alignment
- 3.3 Sand to remove grinding marks and polish if required
- 3.4 Remove the stone from the dop and clean the stone
4. Treat opal specimen
- 4.1 Select opal specimen for treatment and check to ensure it will benefit from treatment
- 4.2 Grind, sand and polish selected area
- 4.3 Treat the selected area
- 4.4 Clean or neutralise as required
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
wax or adhesives for dopping.
Equipment may involve:
appropriate ventilation
grinding machinery
personal protective equipment (PPE)
polishing machinery
sanding machinery
saws.
Jewellers’ cutting angle requirements may include:
10º to 12º side angle (from setting edge to start of dome)
35º to 45º back setting edge (standard solid)
all sharp edges or acute angles to be slightly rounded
flat or domed back
high overall polish and free of defects
proportions of low, medium and high domes to be maintained
sanded or polished back
setting edge to be straight and parallel to back
thickness of stone not to exceed 2/3 of width (standard solid)
tolerance for standard millimetre sizes, 0.2mil. + or −
when leaving potch or boulder on back of stone, maintain proportions in relation to stone size, i.e. approx. 2/3 of width.
General OHS principles and safe operating procedures may include:
complying with the safe operating procedures for each machine or process
good housekeeping
using PPE where required.
Shape and dome may include:
a variety of other shapes
cabochon
dome - high, medium and low
free form
rectangles
shapes.
Treatment may include:
sugar and acid treatment
sugar and heat treatment.
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
wax or adhesives for dopping.
Equipment may involve:
appropriate ventilation
grinding machinery
personal protective equipment (PPE)
polishing machinery
sanding machinery
saws.
Jewellers’ cutting angle requirements may include:
10º to 12º side angle (from setting edge to start of dome)
35º to 45º back setting edge (standard solid)
all sharp edges or acute angles to be slightly rounded
flat or domed back
high overall polish and free of defects
proportions of low, medium and high domes to be maintained
sanded or polished back
setting edge to be straight and parallel to back
thickness of stone not to exceed 2/3 of width (standard solid)
tolerance for standard millimetre sizes, 0.2mil. + or −
when leaving potch or boulder on back of stone, maintain proportions in relation to stone size, i.e. approx. 2/3 of width.
General OHS principles and safe operating procedures may include:
complying with the safe operating procedures for each machine or process
good housekeeping
using PPE where required.
Shape and dome may include:
a variety of other shapes
cabochon
dome - high, medium and low
free form
rectangles
shapes.
Treatment may include:
sugar and acid treatment
sugar and heat treatment.
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:
apply knowledge of the processes for cutting and polishing opals in a range of shapes
achieve a high quality finish that satisfies the requirements of the jewellery industry.
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
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:
apply knowledge of the processes for cutting and polishing opals in a range of shapes
achieve a high quality finish that satisfies the requirements of the jewellery industry.
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
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 |