Rubrics & Criteria

Singapore Crystal Growing Competition

13th Singapore National Crystal Growing Challenge Evaluation Criteria

Junior and Senior Categories        

A. Display Set-up

  • Poster and Display (max. marks 20)
  • The poster should indicate the Name of the students and School along with the Teacher’s name, Purpose statement, Experimental Description, Comments and Conclusion(s). The poster should discuss the problems encountered and how they were tackled. The judges will also be looking for discussion on how the students uncover ways to grow bigger and better quality crystals. Did the students experimented with different crystallization conditions e.g. temperature, concentration, rate of cooling, types of solvent? At least 3 photographs at various stages of crystal growth should be provided. References should be cited where applicable.   
  • Observation Note Book (max. marks 10)
    • Is it dated and properly logged?
    • Are all the experimental procedures and materials used documented?
    • Are all the problems encountered carefully recorded?


    B. Crystal Quality

    • Yield – Teacher must certify in the logbook. Use the percentage yield as a guide (max. marks 10)
    • Faces – Does it have very well defined faces and edges?               (max. marks 10)
    • Occlusions – Are there bubbles or “hair” streaks inside the crystals? Is it transparent? (max. marks 10)
    • Clarity – Is it transparent and clear? Are there scratches or faults on the surfaces? (max. marks 10)
    • Is it single? – Crystals should not be glued or joined together by any other means. (max. marks 10)
    • Edges – Are the edges sharp and not chipped? Are they straight? (max. marks 10)
    • Overall aesthetic quality – Discretionary points awarded by the judges on the overall appeal. (max. marks 10)



    Open Category - “Crystal Tree

    A. Display Set-up

    • The same evaluation criteria and marks will be used. In addition, the poster should also explain the theme of their crystal design and the choice of the chemical materials used. Are they commercially obtained or are they prepared by the students? How are they prepared (include chemical equation where applicable)?
      (max. marks 30 for poster, display and notebook)


    B. Crystal Quality
    • Originality – Is this a novel crystal composition that is different from the rest? Judges will be looking out for creative projects with imaginative themes and also if the crystals are formed as a tree and not different crystals joined together to make a tree. (max. marks 20)
    • Difficulty – Is there an attempt to design and perform the crystallization using methods other than solution techniques e.g. hydrothermal method, flux techniques, crystals in gels. (max. marks 15)
    • Size – Total amount of crystals grown as a tree and how well the branches of the tree are separated with or without the use of any other prop. (max. marks 10)
    • Clarity and Transparency – The criteria mentioned below are applied on the exposed portion of the crystals that makes the crystal tree. Well-defined edges and faces? Faces not broken or chipped? Scratches or defects on the surfaces? Bubbles or “hair” streaks inside the crystals? Clarity? (max. marks 15)
    • Overall aesthetic quality – Discretionary points awarded by the judges on how well the same type of crystals are used to make a well-defined tree and the overall appeal (max. marks 10)