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
communication skills to discuss potential for enhancing stone with colleagues and clients
critical thinking and analytical skills to assess the potential of pieces and choose the best approach
planning and organising skills to select appropriate tools, equipment and materials
numeracy skills to use numerical features of machinery
technical skills to:
choose appropriate stone for cutting
cut, sand and polish opals using correct technique
correct faults and defects.
Required knowledge
characteristics of opal gemstone structure
suitability of opal pieces for carving
opal carving process, including required equipment and consumables
safety issues associated with opal cutting and polishing machinery
industry standards for carving.
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.
Carving tools may include: | assorted mandrels coarse, medium, fine and extra fine wheels diamond grinding burrs of assorted shapes diamond polishing wheels of assorted shapes diamond sanding wheels of assorted shapes felt polishing buffs sanding discs, assorted grit sizes and diameters silicon carbide grinding burrs of assorted shapes supporting equipment: drip feed watering system dust extraction system wooden polishing buffs. |
Carving equipment may include: | air power tools centre point carvers flexible drive hobby carvers micro motor personal protective equipment (PPE). |
OHS issues for carving may include: | contamination eye protection guarding keeping a clean work area minimising dust inhalation maintaining equipment unattended running machinery. |
Sanding mediums may include: | coarse, medium, fine and extra fine wheels of assorted shapes diamond powders up to #1200 on felt/wooden wheels pumice powders on felt wheels sandpaper wheels and discs up to #1200, assorted sizes silicon carbide powders up to #1200 on felt/wooden wheels. |
Polishing compounds may include: | cerium oxide on felt, leather or wooden wheels or discs diamond compounds from #1200 to #100,000 tin oxide. |
Industry practice and expectations may relate to: | no sharp or protruding areas when shaping, keep the setting into jewellery in mind very high polish no grinding marks or sanding marks on surface no cracks or obvious inclusions that should have been removed with initial grinding avoiding making the carving too large considering how strength of colour may affect the need for detail. |
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