SAQA All qualifications and part qualifications registered on the National Qualifications Framework are public property. Thus the only payment that can be made for them is for service and reproduction. It is illegal to sell this material for profit. If the material is reproduced or quoted, the South African Qualifications Authority (SAQA) should be acknowledged as the source.
SOUTH AFRICAN QUALIFICATIONS AUTHORITY 
REGISTERED UNIT STANDARD THAT HAS PASSED THE END DATE: 

Crosswork bottom blocking on diamond gemstones 
SAQA US ID UNIT STANDARD TITLE
260459  Crosswork bottom blocking on diamond gemstones 
ORIGINATOR
SGB Mining and Minerals 
PRIMARY OR DELEGATED QUALITY ASSURANCE FUNCTIONARY
-  
FIELD SUBFIELD
Field 06 - Manufacturing, Engineering and Technology Fabrication and Extraction 
ABET BAND UNIT STANDARD TYPE PRE-2009 NQF LEVEL NQF LEVEL CREDITS
Undefined  Regular  Level 4  NQF Level 04  6 
REGISTRATION STATUS REGISTRATION START DATE REGISTRATION END DATE SAQA DECISION NUMBER
Passed the End Date -
Status was "Reregistered" 		 2018-07-01  2023-06-30  SAQA 06120/18 
LAST DATE FOR ENROLMENT LAST DATE FOR ACHIEVEMENT
2026-06-30   2029-06-30  

In all of the tables in this document, both the pre-2009 NQF Level and the NQF Level is shown. In the text (purpose statements, qualification rules, etc), any references to NQF Levels are to the pre-2009 levels unless specifically stated otherwise.  

This unit standard does not replace any other unit standard and is not replaced by any other unit standard. 

PURPOSE OF THE UNIT STANDARD 
This unit standard is useful for people who intend following a career in the diamond processing sector and who are required to crosswork bottom blocking on diamond gemstones.

Learners credited with this unit standard are able to:
  • Identify the equipment and tools used to crosswork bottom blocking on diamond gemstones and describe their application.
  • Demonstrate knowledge of the structure of diamond gemstones and the implications for crossworking diamond gemstones.
  • Locate diamond gemstones into and set tangs for crossworking bottom blocking.
  • Prepare the four bottom corners and pavilions on diamond gemstones.
  • Conduct post-bottom blocking cleaning, checking and security activities.

    The skills, knowledge and understanding demonstrated within this unit standard are essential for social and economic transformation and contribute to the upliftment and economic growth of the mining and minerals sector, particularly in the aspect of beneficiation.

    This unit standard is intended to promote general skills, knowledge and understanding of the diamond processing industry in the mining and minerals sector in order to ensure knowledgeable and informed workers. 
    		•

    LEARNING ASSUMED TO BE IN PLACE AND RECOGNITION OF PRIOR LEARNING 
    It is assumed that learners are already competent in:
  • Advance use of loupe to examine diamond gemstones.
  • Identify polishing grains and planes in diamond gemstones.
  • Explain the requirements for security of diamonds.
  • Prepare a scaiffe for crossworking diamond gemstones.
  • Prepare and set up a bench for crossworking diamond gemstones.
  • Process diamonds at the Level of the NQF Level 3 national certificate. 
    		•

    UNIT STANDARD RANGE 
  • The scope and context applies to the conversion of rough diamond gemstones into cut and polished diamond gemstones for sale into local and international markets.
  • This unit standard applies to persons crossworking any diamond gemstones under minimal supervision. 
    		•

    Specific Outcomes and Assessment Criteria: 

    SPECIFIC OUTCOME 1 
    Identify the equipment and tools used to crosswork bottom blocking on diamond gemstones and describe their application. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    The tools and their components used to crosswork bottom blocking on diamond gemstones are identified and their use in different applications is explained in terms of key features, applications and methods for use. 

    ASSESSMENT CRITERION 2 
    The importance of bottom blocking for crossworking is explained in relation to the process of crossworking and the proportions of the finished polished diamond gemstone. 

    ASSESSMENT CRITERION 3 
    Practices are explained to maintain good housekeeping, safety in the workplace and care of equipment in line with workplace specific requirements. 

    ASSESSMENT CRITERION 4 
    The consequences of deviating from workplace specific practices are described in terms of potential impact on health, safety, equipment, products and productivity. 

    SPECIFIC OUTCOME 2 
    Demonstrate knowledge of the structure of diamond gemstones and the implications for crossworking diamond gemstones. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    Two, three and four points in rough diamond gemstones are identified for different diamond types. 

    ASSESSMENT CRITERION 2 
    The polishing grains in two, three and four point stones are identified in terms of the crystallography of diamonds. 

    ASSESSMENT CRITERION 3 
    Problems that can be encountered when crossworking sawn and makeable diamond gemstones are described in terms of types of problems, key features, implications for polishing and methods to overcome such problems. 
    ASSESSMENT CRITERION RANGE 
    The types of problems that can be encountered must include:
  • Gletzes.
  • Naat.
  • Cross-grain.
  • Holes.
  • Flaws.
  • Impurities.
  • Naturals.
     
    		•

    ASSESSMENT CRITERION 4 
    Advanced faceting hints and techniques for crossworking bottom blocking on diamond gemstones for sawn and makeable stones are explained in terms of different applications and the consequences of using inappropriate crossworking techniques. 

    SPECIFIC OUTCOME 3 
    Locate diamond gemstones into and set tangs for crossworking bottom blocking. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    Appropriate personal protective clothing and equipment is selected and applied according to required standards of occupational health and safety. 

    ASSESSMENT CRITERION 2 
    Stones received are set in an appropriate pot and located in polishing tangs for crossworking bottom blocking according to workplace specific operating procedures. 

    ASSESSMENT CRITERION 3 
    Appropriate tang selection is made for crossworking bottom blocking according to workplace specific operating procedures. 

    ASSESSMENT CRITERION 4 
    A scaiffe is ensured to have been correctly prepared for crossworking bottom blocking before putting the stone on the scaiffe. 

    ASSESSMENT CRITERION 5 
    Occupational health and safety hazards are monitored during setting and clamping and remedial action is taken where necessary. 

    SPECIFIC OUTCOME 4 
    Prepare the four bottom corners and pavilions on diamond gemstones. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    Stones are bottom blocked using the appropriate methodology to address the given problems in line with the requirements as indicated by the Marker and within defined quality and output standards. 
    ASSESSMENT CRITERION RANGE 
    Indications by the Marker and defined quality and output standards will be found in the employer's:
  • Work specifications.
  • Tariff agreements.
  • Parcel instructions.
  • Policies and Procedures.
     
    		•

    ASSESSMENT CRITERION 2 
    The scaiffe is frequently checked for any defects during the process of crossworking. Remedial action is taken in line with workplace specific procedures. 

    ASSESSMENT CRITERION 3 
    Occupational health and safety hazards are monitored during crossworking and remedial action is taken where necessary. 

    ASSESSMENT CRITERION 4 
    Weights of diamond gemstones are ensured to be within the laid down tolerance levels after crossworking bottom blocking. 
    ASSESSMENT CRITERION RANGE 
    Laid down tolerance levels will be found in the employer's:
  • Work specifications.
  • Tariff agreements.
  • Policies and Procedures.
     
    		•

    SPECIFIC OUTCOME 5 
    Conduct post-bottom blocking cleaning, checking and security activities. 

    ASSESSMENT CRITERIA     

    ASSESSMENT CRITERION 1 
    Diamond gemstones are removed from pots after crossworking for bottom blocking, cleaned and inspected for quality of finish in relation to workplace specifications. Remedial action required is taken in line with workplace specific procedures. 

    ASSESSMENT CRITERION 2 
    Housekeeping is exercised after crossworking bottom blocking on diamond gemstones in accordance with workplace procedures. 
    ASSESSMENT CRITERION RANGE 
    Good housekeeping must include:
  • Clean pots and tangs.
  • Replace pots and tangs into correct storage facilities.
  • Maintenance of personal protective clothing and equipment.
     
    		•

    ASSESSMENT CRITERION 3 
    Diamond gemstones are accounted for after crossworking bottom blocking in terms of the workplace security system. 


    UNIT STANDARD ACCREDITATION AND MODERATION OPTIONS 
  • Anyone assessing a learner or moderating the assessment of a learner against this unit standard must be registered as an assessor with the relevant Education, Training, Quality, Assurance (ETQA) Body, or with an ETQA that has a Memorandum of Understanding with the relevant ETQA.
  • Any institution offering learning that will enable the achievement of this unit standard must be accredited as a provider with the relevant Education, Training, Quality, Assurance (ETQA) Body, or with an ETQA that has a Memorandum of Understanding with the relevant ETQA.
  • Assessment and moderation of assessment will be overseen by the relevant Education, Training, Quality, Assurance (ETQA) Body, or with an ETQA that has a Memorandum of Understanding with the relevant ETQA, according to the ETQA's policies and guidelines for assessment and moderation.
  • Moderation must include both internal and external moderation of assessments, unless ETQA policies specify otherwise.
  • Anyone wishing to be assessed against this unit standard may apply to be assessed by any assessment agency, assessor or provider institution that is accredited by the relevant ETQA. 
    		•

    UNIT STANDARD ESSENTIAL EMBEDDED KNOWLEDGE 
    The following embedded knowledge is addressed in an integrated way in the unit standard.

    Knowledge relating to the properties of a diamond gemstone:
  • Understanding the various properties of the diamond and the effect that crossworking may have.
  • The action that the different components of the polishing equipment may have on the diamond.
  • Importance of equipment being level for crossworking.
  • Awareness of the damage to a diamond that can be caused by equipment that is not level, or where the diamond is not properly applied to the scaiffe.

    Occupational Health, Safety and Environmental issues:
  • Significant hazards and risks related to gemstone processing, their consequences and mitigating actions.
  • Safety measures related to diamond processing.
  • PPE requirements and the reason for each.
  • Impact on the environment and mitigating actions.
  • Emergency procedures.

    Legislative and structural environment:
  • Importance of adherence to health and safety requirements during processing.
  • Importance of care and maintenance of tools and equipment.
  • Codes of practice.

    Communication:
  • Reporting requirements and ability.
  • Communicating with relevant personnel.
  • Liaison between personnel in various functions.
  • Understanding terminology.

    Handling and custody of diamond gemstones:
  • Achieving specified production requirements.
  • Identify the equipment and explain the specification and functions.
  • Preparation.
  • Examination.
  • Handling of diamond gemstones.
  • Monitoring and control.

    Monitoring processing and impurities:
  • Weight loss.
  • Security requirements.
  • Collection and disposal of diamond dust.
  • Use of tools and equipment.
  • Use of personal protective equipment. 
    		•

    UNIT STANDARD DEVELOPMENTAL OUTCOME 
    N/A 

    UNIT STANDARD LINKAGES 
    N/A 


    Critical Cross-field Outcomes (CCFO): 

    UNIT STANDARD CCFO IDENTIFYING 
    Identify and solve problems and make decisions using critical and creative thinking.
  • Note: The ability to identify impurities in diamond gemstones and be able to take the appropriate action in processing the gemstone, and to interpret the instructions from the Marker and make decision on how to crosswork illustrates the capability to solve problems. 
    		•

    UNIT STANDARD CCFO WORKING 
    Work effectively with others as members of a team, group, organisation or community.
  • Note: The ability to communicate effectively and to maintain optimum production illustrates the capability to work effectively with others. 
    		•

    UNIT STANDARD CCFO ORGANISING 
    Organise and manage themselves and their activities responsibly and effectively.
  • Note: The ability to maintain optimum production whilst adhering to safety and security procedures, illustrates the capability to organise and manage themselves and their activities responsibly and effectively. 
    		•

    UNIT STANDARD CCFO COLLECTING 
    Collect, analyse, organise and critically evaluate information.
  • Note: The ability to interpret instructions from the Marker/in the parcel in relation to the stone and implement corrective actions indicates the ability to analyse, organise and critically evaluate information. 
    		•

    UNIT STANDARD CCFO SCIENCE 
    Use science and technology effectively and critically showing responsibility towards the environment and health of others.
  • Note: The ability to apply tools and equipment appropriately to effect crossworking of diamonds and to organise equipment and machinery effectively illustrates the capability to use science and technology. 
    		•

    UNIT STANDARD ASSESSOR CRITERIA 
    N/A 

    REREGISTRATION HISTORY 
    As per the SAQA Board decision/s at that time, this unit standard was Reregistered in 2012; 2015. 

    UNIT STANDARD NOTES 
    Terminology:

    Specified Requirements:

    Specified requirements include legal and site-specific requirements and are contained in one or more of the following documents:

    Legal:
  • The Bargaining Council for the Diamond Cutting Industry Main Agreement.
  • Regulations of the Diamonds Act, No 56 of 1986, as amended.
  • Occupational Health and Safety Act (Act 85/1993).
  • Mandatory Codes of Practice.
  • The glossary of terms about the terminology of the industry issued by the Bargaining Council for the Diamond Cutting Industry.

    Site-Specific:
  • Hazard Identification and Risk Assessments (HIRA).
  • Occupational Health and Safety Risk Management Programme.
  • Managerial Instructions.
  • Workplace diamond gemstone security system.
  • Working Guides, tariff agreements, policies and procedures.
  • Equipment and Materials Specifications. 
    		•

    QUALIFICATIONS UTILISING THIS UNIT STANDARD: 
      ID QUALIFICATION TITLE PRE-2009 NQF LEVEL NQF LEVEL STATUS END DATE PRIMARY OR DELEGATED QA FUNCTIONARY
    Elective  64729   Further Education and Training Certificate: Diamond Processing  Level 4  NQF Level 04  Passed the End Date -
    Status was "Reregistered"     		 2023-06-30  MQA 


    PROVIDERS CURRENTLY ACCREDITED TO OFFER THIS UNIT STANDARD: 
    This information shows the current accreditations (i.e. those not past their accreditation end dates), and is the most complete record available to SAQA as of today. Some Primary or Delegated Quality Assurance Functionaries have a lag in their recording systems for provider accreditation, in turn leading to a lag in notifying SAQA of all the providers that they have accredited to offer qualifications and unit standards, as well as any extensions to accreditation end dates. The relevant Primary or Delegated Quality Assurance Functionary should be notified if a record appears to be missing from here.
     
    NONE 


    All qualifications and part qualifications registered on the National Qualifications Framework are public property. Thus the only payment that can be made for them is for service and reproduction. It is illegal to sell this material for profit. If the material is reproduced or quoted, the South African Qualifications Authority (SAQA) should be acknowledged as the source.