Diamond Grading & Sorting

Paper Code: 
JWT 504(B)
Credits: 
08
Contact Hours: 
120.00
Max. Marks: 
100.00
Objective: 

 

This course will enable the students to-

  1. Grade diamonds consistently and accurately using a modern gem microscope and loupe.
  2. Recognize the most common diamond features.
  3. Study of 4 ‘C’s of diamonds, Use of various Gemology instruments.

Learning outcomes (COs):

Course

Learning outcomes

(at course level)

Learning and teaching strategies

Assessment

Strategies

Paper Code

Paper Title

JWT 504(B)

 

Diamond Grading & Sorting

The students will be able to –

 

CO96: Use basic gemological instruments.

 CO97: Learn about different diamond testing equipment.

CO98:  Learn about the use of this equipment for the purpose of gemstone identification.

CO99: Learn about different properties of Diamonds which will be helpful in their identification.

 

Approach in teaching: Interactive Practical Sessions , Theme board  , Demonstrations ,Giving tasks, Field practical , inspiration board,  Workshop ,  Laboratory industry visits,  Group and Team work

Learning activities for the students: Self-learning assignments, Effective , Product and Design development

Class test, Semester end examinations, Assignments, Presentation, Individual and group projects

 

20.00
Unit I: 
Uses of various instruments:

Refract meter, Polariscope, Microscope, Spectroscope, Ultraviolet lamp , Hardness pencil ,  Diamond probe, Chelsa  filter, 10x lens. MM Watch, optimizer, sieve  etc

 

20.00
Unit II: 
Properties of Diamond

The physical properties of diamond and their practical exploitation. Dispersion and ‘fire; total internal reflection; reflectivity and luster;brilliance.

Directional optical properties; durability, specific gravity (SG), electrical properties; thermal properties; wettability.

Non – optical directional properties; ‘grain’ cleavage, differential hardness and crystal from in relation to the crystal structure of diamond; their significance in identification and manufacture.

 

30.00
Unit III: 
4 C’s of Diamonds and grading
  • Cut Grading of diamonds : Ideal proportions for diamond brilliant cut (GIA)
  • Table angle and depth
  • Crown angle and height
  • Girdle thickness and angle
  • Pavilion angle and depth
  • Clarity Grading
  • Types of inclusions in diamond
  • Types of Blemisses
  • Percentages of inclusions and blemisses
  • Clarity chart (GIA)
  • Color Grading
  • Using color master
  • Color scale of diamond (GIA)
  • Carat Weight and size
  • Unit weight of Cents(Ct) carat weight
  • Use of Millimeter Gauge

 

20.00
Unit IV: 
Color in Diamond

                                

  • Color Grading
  • Grade diamonds in the D-to-Z color range
  • Detect laboratory-grown diamonds, treatments, and stimulants

 

30.00
Unit V: 
Clarity grading

                              

  • Practical clarity grading
  • Internal & External features which effects clarity grading
  • Grading and sorting of diamonds from small size to solitaire
  • Examine various diamond samples with 10x lens and under microscope. Practice of grading them according to grading charts.

 

Essential Readings: 

Books Recommended:

  • Spear, K. E., & Dismukes, J. P. (Eds.). (1994). Synthetic diamond: emerging CVD science and technology (Vol. 25).
  • John Wiley & Sons. Neves, A. J., & Nazaré, M. H. (Eds.). (2001). Properties, growth and applications of diamond IET.
  • Smith, G. (2003). The allure, magic and mystery-A brief history of diamonds. Journal of the Southern African Institute of Mining and Metallurgy, 103(9), 529-534.
  • Kendall, L. P. (2001). Diamonds: Famous and Fatal: the History, Mystery, and Lore of the World's Most Precious Gem. Barricade Books.
  • Pagel-Theisen, V. (2001). Diamond grading ABC: The manual. Rubin & Son.

 

 

 

 

Academic Year: 
2020-2021
  • Printer-friendly version
  • PDF version