It have all description regarding diamond.

1. SEMINAR ON
DIAMOND
By:-
Saurabh Kumar Mishra

2. Contents
• Introduction
• Classification of Diamond
• Physical Properties of Diamond
• Optical Properties of Diamond
• Distinguish Properties
• Diamond Cutting
• Genesis of Diamond
• Diamond in India
• World occurrence of Diamond
• Conclusion
• References

3. Introduction
• Diamond is a rare, naturally-occurring
gemstone composed of carbon.

5. Introduction
Diamond is a rare, naturally-occurring
gemstone composed of carbon.
Each carbon atom in a diamond is
surrounded by four other carbon atoms
and connected to them by strong covalent
bonds.
• It is chemically resistant and it is the
hardest known natural substance.

6. Classification of Diamond
Diamond
Type- I  Consist of nitrogen atoms
in varying proportion
Type- II

7. Classification of Diamond
Diamond
Type- I
Type- Ia
Type- Ib
Nitrogen content 0.1%
i.e. 1:1000 atoms
Nitrogen content very
less
i.e. 1:1.000,000 atoms
Type- II

8. Classification of Diamond
Diamond
Type- I
Type- Ia
Type- Ib
Type- IaA
Type- IaB
•Wherein along with
the platelets.
•nitrogen occurs as
pairs of atoms.
•Nitrogen forms larger
clusters
•containing an even
number of atoms.
Type- II

9. Classification of Diamond
Diamond
Type- I
Type- II
Type- Ia
Type- Ib
Type- IaA
Type- IaB
Do not have significant
amount of nitrogen.
Consist of boron in the
lattice.
Thermal conductivity is
about three times that of
type I.

10. Classification of Diamond
Diamond
Type- I
Type- II
Type- Ia
Type- Ib
Type- IIa
Type- IaA
Type- IaB
Paucity of both nitrogen
and boron.
Enhanced optical and
thermal properties.
Type- IIb

11. Classification of Diamond
Diamond
Type- I
Type- II
Type- Ia
Type- Ib
Type- IIa
Type- IIb
Type- IaA
Type- IaB
Presence of boron
atoms in solid solution.
Extremely rare in nature.

12. Classification of Diamond
Diamond
Type- I
Type- II
Type- Ia
Type- Ib
Type- IIa
Type- IIb
Type- IaA
Type- IaB

13. Physical Properties of
Diamond
Cleavage Perfect 4 Set octahedral
Colour Colourless, White, Gray, Black, Blue
Specific Gravity 3.5 - 3.53, Average = 3.51
Diaphaneity Transparent to Sub-transparent to translucent
Fracture Conchoidal
Habit well-formed crystals showing good external form
Hardness 10
Luster Adamantine
Streak colorless
Chemical Formula C

14. Optical Properties of
Diamond
Type Isotropic
Refractive Index 2.418
Birefringence None
Pleochroism None
Dispersion High, 0.044
Surface Relief Moderate

15. DISTIGUISHING PROPERTIES OF NATURAL DIAMOND
AND SYNTHETIC DIAMOND (CUBIC ZIRCONIA)
NATURAL DIAMOND
 Specific gravity is 3.52
 High thermal conductivity
 Transparent to X-rays
SYNTHETIC VARIETY
(CUBIC ZIRCONIA)
 Here it is 4.55 to 7.05 more
heavier than natural ones
 Low thermal conductivity
 Less transparent and
leaves a marked
impression

16. Breath test:- the mist created by breathing on gem
diamond clears faster than other stimulants.
Sticky test:- diamond sticks to fingers better than other
stones which fall when attempted to pick up by moistened
fingers.
Droplet test:- a drop of water on a thoroughly cleaned
surface of a diamond remains as a high domed globule
whereas in stimulants it spreads faster.
MISSCELANEOUS TEST

17. Diamond Anatomy
• A diamond is comprised of five main
components:
Table
Crown
Girdle
Pavilion
Culet

18. • One of the most defining characteristics of
a diamond is its cut.
• An expertly cut diamond will achieve high
levels of brilliance, sparkle, and durability.
• Even if a diamond is graded well in other
areas, a poor cut can result in a
dull, muted effect.
Diamond Cutting

19. Diamond Cutting
 A particular proportion of cutting is essential to bring about brilliance
in a stone.
 It is emphasized into two aspects
 Ratio of proportion of crown and pavilion
 Angle of cut on crown and pavilion facets w.r.t girdle
 Depending on critical angle a stone is cut at a particular angle to
obtain total internal reflection so that light refracted into a stone is
completely thrown back like a mirror, this aspect is illustrated taking
diamond as an example provided below:

20. Genesis of Diamond
 Diamonds form about 100
miles below the Earth's
surface.
 In order for a diamond to be
created, carbon must be
placed under at least 435,113
pounds per square inch of
pressure at a temperature of at
least 752 degrees
Fahrenheit (400 Celsius).
 If conditions drop below
either of these two points,
graphite will be created.

21. Genesis of Diamond
Four processes are thought to be responsible for virtually all of the natural
diamonds that have been found at or near Earth's surface. One of these processes
accounts for nearly 100% of all diamonds that have ever been mined. The remaining
three are insignificant sources of commercial diamonds.

22. 1) Deep Source Eruptions
 Most commercial diamond
deposits are thought to have
formed when a deep-source
volcanic eruption delivered
diamonds to the surface. In
these eruptions magma
travels rapidly from deep
within the mantle, often
passing through a diamond
stability zone on its route to
the surface. Pieces of rock
from the diamond stability
zone may be torn free and
carried rapidly upwards to
the surface. These pieces of
rock are known as
"xenoliths" and may contain
diamonds.

23. Continue….
 Most diamonds that we see today were formed
millions of years ago. Powerful magma eruptions
brought the diamonds to the surface, creating
kimberlite pipes (named after Kimberly, South
Africa).

24. 2) Subduction Zone Diamonds
 Diamonds have been
found in rocks that are
thought to have been
subducted and then
returned to the surface.
These types of rocks
are very rare and no
known commercial
diamond deposits have
been developed within
them. The diamonds
found in these types of
deposits have been
very small and not
suitable for commercial
use.

25. 3) Asteroid Impact Diamonds
 Diamonds have been found in
and around the craters of
asteroid impact sites. These
asteroids hit with such force
that pressures and
temperatures high enough to
form diamonds are produced.
If the target rock contains
carbon the conditions needed
to form diamonds might occur
within the impact area. These
types of diamonds are rare
and do not play an important
role in commercial diamond
mining.

26. 4) Diamonds Formed in Space
• Diamonds have
been discovered
in some
meteorites.
These diamonds
are thought to
have formed in
space in
response to
asteroid impacts.

27. Diamond in India

28. Panna Mine, Madhya Pradesh

29. World occurrence of Diamond
 Diamonds are mostly found in Africa, India, Russia (Siberia),
South America, Australia, China, and Canada. A good sign
that diamonds are in the area is where kimberlite rock is found.

30. CONCLUSION
 Compared to most other gem- minerals, the
percentage of gem quality crystals is quite high in
diamond.
 Kimberlite, lamproite and eclogate are the major
sources of diamond.
 About 20% of diamonds recovered is of gem quality.
The other 80% is been used as industrial diamonds.
 Its high hardness, fire ,adamantine lustre, brilliance
have made Diamond most valuable gem mineral.
 So if our country have more diamond deposits, we can
make our country more prosperous.

31.  R.V. Karanth (2000), Gems and Gem Industry In India, GSI, Pp 165-197
 Cornelis(2002) Klein & Barbara Dutrow, Mineral Science(after James D.
Dana), John Wiley & Son INC, Pp 557-558.
 T.M. Babu (1998),, Diamonds in India, GSI, Pp 45,92-94.
 www.authorstream.com/Presentation/Ariane-26975-Diamond-Diamondat-
glance-HISTORY-DIAMONDS-Early-Middle-Ages-Recent-Times-as-
Entertainment-ppt-powerpoint/
 www.minerals.net/gemstone/diamond_gemstone.aspx
 http://geology.com/minerals/diamond.shtml
References