Structure property relationship of Diamond

1. Subject- Industrial Chemistry
Topic- Structure-Property
Relationship of Diamond
Roll No : C-49
Guided by – DR. Y.P. Patil sir
By- Tejas Bhaulal Patil

2. Structure of Diamond
 In Mineralogy Diamond is metastable allotrope of carbon
 Most natural Diamonds are formed at high temperature
and pressure at depths of 140 to 190 km in Earth’s mantle
 In Diamond , the carbon atoms are arranged tetrahedrally
( sp³ hybridisation of C ) ; each Carbon atom is linked to
its neighbours by four single covalent bonds . This leads to
a three – dimensional network of covalent bonds.
 Crystal Structure : Octahedral
 Density : 3.3 - 3.5 g/m³

3. Crystal Lattice of Diamond

4. Properties of Diamond :
 Diamonds are chemically stable.
 Diamonds are naturally Liophilic and Hydrophobic.
 Physical Properties :
1. Has a very high melting point ( almost 4000°C )
2. Is very Hard. This is again due to the need to break
Very strong covalent bonds .
3. Doesn’t conduct electricity as electrons cannot flow due
to the rigidity of structure.
4. Is Insoluble in water and Orgnic solvents.

5. 5. Hardness is directional : some cases the hardest direction
100 times harder than the softest direction.
6. Highly lusturous face
7. Triangular shaped growth defects present
8. Flattest and sharp facets and facet edges .
 Thermal Conductivity :
Good conductor of heat . Thermal conductivity of natural
diamond is about 22 W/cm K .
 Electrical Properties :
1. Good electrical insulator , resistivity of 10¹¹ to 10¹⁸ ohm/m
2. Magnetic properties observed in diamond nanocrystals.

6.  Optical Properties :
Diamond has a wide bandgap of 5.5 ev corresponding to the
deep ultraviolet wavelength of 225 nm . This means pure
diamond should transmit visible light and appear as a clear
colourless crystal . Colours in diamond originate from lattice
defects and impurities . The diamond crytal lattice is
exceptionally strong and only atoms of nitrogen , boron and
hydrogen can be introduced into diamond during the growth
at significant concentrations

7. Nitrogen is the most common impurity found in gem
diamonds and is responsible for the Yellow and the Brown
colour in Diamonds. Boron is responsible for the blue colour.

8. References
 Structure and Properties of Diamond-Like Phases by
Vladimir Greshnyakova and Evgeny Belenkovb
 Chanaka Wickramasinghe , Mineral Resources and
technology degree program.

9. Acknowledgement
 I would like to express to deepest appreciation and sense of gratitude
to my guide, Dr.Y.P
. Patil sir whose valuable guidance has helped me
to complete this presentation . His suggestions and instructions have
served as a major contributor towards this outcome.

10. THANK YOU