Copy and paste from the following data to produce each assessment task. Write these in plain English and spell out how, when and where the task is to be carried out, under what conditions, and what resources are needed. Include guidelines about how well the candidate has to perform a task for it to be judged satisfactory.
Required skills
planning and organising skills to select and prepare opal backing materials for cutting
problem-solving skills to identify and address common problems associated with pre-cutting processes
numeracy skills to use numerical features of machinery
technical skills to:
complete pre-cutting processes for opal doublets and triplets using correct technique and equipment
work safely with opal-cutting 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.
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. |
Copy and paste from the following performance criteria to create an observation checklist for each task. When you have finished writing your assessment tool every one of these must have been addressed, preferably several times in a variety of contexts. To ensure this occurs download the assessment matrix for the unit; enter each assessment task as a column header and place check marks against each performance criteria that task addresses.
Observation Checklist