Application
This unit requires the application of knowledge and skills to cut and polish opals on a continuous basis producing pieces that comply with trade requirements. The cutting must be done in such a way that the cutting business is viable and the stone meets trade requirements. The skill is applied in a workshop environment and includes stock control and record keeping. A major application of this competency is in the manufacture of triplets. |
Prerequisites
This unit may be assessed on its own or it may be assessed with other units that cover related skills and knowledge. Evidence is most relevant when provided through an integrated activity which combines the Elements of competency for the unit, or a cluster of units of competency. |
Elements and Performance Criteria
ELEMENT | PERFORMANCE CRITERIA |
1 Select the machinery and consumables for production cutting opal. | 1.1 Select the machinery. 1.2 Select the consumablesandadhesives. 1.3 Select the lighting equipment for UV sensitive adhesives. 1.4 Obtain Materials Safety Data Sheets for all materials used. |
2 Identify sources of rough opal and consumables and obtain supplies. | 2.1 Determine sources and cost of rough opal and obtain supplies. 2.2 Determine sources and cost of consumables including backing material and triplet tops and obtain supplies. 2.3 Record information about suppliers and costs. 2.4 Set up stock management system. |
3 Review the layout of the workshop and set up machinery and equipment for production cutting. | 3.1 Review the layout in relation to production cutting and make adjustments to facilitate workflow where required. 3.2 Set up multi-blade saw to manufacturers' specifications. 3.3 Set up grinder, sander, polisher and lighting equipment. 3.4 Set up dopping rack and other racks and containers as needed. |
4 Cut and polish opal to industry requirements within the time constraints of the production process. | 4.1 Cut and polish opals to trade requirements within the predetermined time constraints. 4.2 Use appropriate dopping techniques for production work. 4.3 Ensure opals satisfy trade requirements for standard millimetre sizes for particular applications. 4.4 Follow all OHS requirements for machinery, equipment and consumables. |
Required Skills
Required skills: set up and use production equipment source materials cost materials follow the procedures for stock management servicing and testing of equipment. |
Required knowledge: differentiate between standard and production cutting knowledge of the procedures and equipment used in production cutting where to locate and cost materials for production cutting knowledge of stock management requirements. |
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. | |
Critical aspects for assessment and evidence required to demonstrate competency in this unit | To achieve competency in this unit, a person must be able to cut opal in a production environment meeting standards of quality and working with commercial constraints. The assessment must confirm the ability to select machinery and consumables; to organise the workshop for production cutting and cut opals to industry standards within commercial constraints. All OHS issues must be handled appropriately. Competence in this unit must be assessed over a period of time in order to ensure consistency of performance over the range of variables and contexts applicable to the work environment. |
Context of and specific resources for assessment | This unit may be assessed in a work environment, in a simulated work environment or in a combination of these situations. |
Method of assessment | For valid and reliable assessment of this unit, evidence should be gathered through a range of methods to indicate consistent performance. Assessment of this unit of competence will usually include observation of processes and procedures, oral and/or written questioning on underpinning knowledge and skills and other methods as required. 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). |
Assessment of this competency requires access to: production cutting and polishing equipment, tools and consumables a qualified workplace assessor or assessment team. |
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. | |
Machinery may include: | cabochon cutting machine cabochon pre-former |
diamond sintered wheel grinder faceting unit pre-former high speed sanding unit multi bade trim saw pumice pre-polishing unit soft diamond wheel sanding and polishing unit spongy wheel sanding unit triplet slicing machine UV light box vibro tumbler. | |
Consumablesand adhesives may include: | #400 acid treated silicon-carbide powder backing material blackening agent dopping wax or adhesive epoxy adhesive grinding wheels polishing powder (cerium oxide) polishing wheels (diamond or felt) red sealing wax rough opal sanding wheels (diamond or spongy) trim saw blades triplet slicing blades, 120, 140, 160,180. triplet tops UV adhesive water and electricity. |
Backing materials may include: | black jade black potch (best) boulder iron stone clear or transparent potch dark grey potch glass (triplet only) obsidian (black) vitrolite (triplet only). |
Stock management system may include: | avoiding cutting irregular sizes or shapes to minimise slow stock maintenance of rough opal and consumables supplies regular checks with suppliers for continuity of consumables stock popular sizes to meet new markets. |
Dopping techniques may include: | 5-minute epoxy glue aluminium or wooden dop-sticks collapsible rack for holding dop-sticks green or red sealing wax vacuum dopping wood glues. |
Standard millimetre sizes may require: | consistent accurate sizes no grinding marks or sanding marks on surface very high polish required when shaping, keep the setting into jewellery in mind. |
Sectors
Not Applicable
Competency Field
Opal cutting and polishing | |
Employability Skills
This unit contains employability skills. |
Licensing Information
Refer to Unit Descriptor