Just an glimpse on understanding of basic mineralogical terminologies for the freshers in the field of Metals and minerals. I did this because in the preparation medicine from the metals and minerals origin we must know the basics of Metallurgy ..if anyone interested in this ppt let me know I'll post more presentation.......

1. SEMINAR ON SP.
GRAVITY,
HARDNESS,TENACITY,
POROSITY,
FISIBILITY
By Dr. Bankimchandra S J
PG Scholar

2. SIGNIFICANCE OF SP.
GRAVITY
• Two minerals may be of the same size, but their weight may
be very different. The specific gravity of a mineral determines
how heavy it is by its relative weight to water.
• Ex: Water has a specific gravity of 1.0. If a mineral has a
specific gravity of 2.7, it is 2.7 times heavier than water.
Minerals with a specific gravity under 2 are considered light,
between 2 and 4.5 average, and greater than 4.5 heavy.

3. SPECIFIC GRAVITY: METHODS
OF DETERMINING SPECIFIC
GRAVITY
• A number of experimental methods for determining the
specific gravities of solids, liquids, and gases have been
devised. A solid is weighed first in air, then while immersed
in water; the difference in the two weights, according to
Archimedes' principle , is the weight of the water displaced
by the volume of the solid. If the solid is less dense than
water, some means must be adopted to fully submerge it,
• e.g., a system of pulleys or a sinker of known mass and
volume. The specific gravity of the solid is the ratio of its
weight in air to the difference between its weight in air and
its weight immersed in water.

4. TYPES• Picnometer
A gas pycnometer is a laboratory device used for measuring the density—or, more
accurately, the volume—of solids, be they regularly shaped, porous or non-
porous, monolithic, powdered, granular, employing some method of gas displacement and
the volume :
Pressure relationship known as Boyle's Law.
A gas pycnometer is also called as a helium pycnometer
Applications.
Gas pycnometers are used extensively for characterizing a wide variety of solids such
as heterogeneous catalysts, carbons,metal powders, soils,ceramics,active pharmaceutical
ingredients (API's) and excipients, petroleum coke,cement and other construction
materials,cenospheres/glass microballoons and solid foams.
.

5. HYDROMETER
• Hydrometer: Usually a cylindrical glass stem with a scale
inside, and a bulb at one end weighted with mercury or lead.
When lowered into a container of liquid, the calibrated glass
stem will float freely in the fluid. Using the point where the
fluid surface touches the stem, a reading of the specific
gravity can be taken directly from the scale it worked based
on the concept of buoyancy.

6. PRINCIPLE OF
HYDROMETER
• This technology relies upon Pascal's Principle which states
that the pressure difference between two points within a
vertical column of fluid is dependent upon the vertical
distance between the two points,

7. SPECIFIC-GRAVITY BOTTLE
• A flask made to hold a known volume of liquid at a
specified temperature (usually 20°C). The bottle is weighed,
filled with the liquid whose specific gravity is to be found,
and weighed again. The difference in weights is divided by
the weight of an equal volume of water to give the specific
gravity of the liquid. For gases a method essentially the same
as the bottle method for liquids is used. Specific gravities of
gases are usually converted mathematically to their value at
standard temperature and pressure

8. SPECIFIC GRAVITY
• Defn :it is the ratio of the mass of a substance to the mass of
a reference substance for the same given volume.

9. IMPORTANCE
• When it comes to configuring a mixture knowing sp.gravity
of substance will influence the Torque and Horse power to
mix properly.
• (Higher the Sp. Gr. , More Torque)

11. MOHS HARDNESS SCALE

12. HARDNESS
• Hardness is measured by the resistance which a smooth
surface offers to abrasion. The degree of hardness is
determined by observing the comparative ease or difficulty
which one mineral is scratched by another

16. TENACITY

18. POROSITY OR VOID
FRACTION
• A measure of the void (i.e. "empty") spaces in a
material, and is a fraction of the volume of voids over the
total volume, between 0 and 1, or as a percentage between
0% and 100%.

19. MEASURMENT
• Direct methods (determining the bulk volume of the porous sample, and then
determining the volume of the skeletal material with no pores
• (pore volume = total volume − material volume).
• Optical methods :- (e.g., determining the area of the material versus the area of
the pores visible under the microscope).
• The "areal" and "volumetric" porosities are equal for porous media with
random structure.
• Computed tomography method (using industrial C.T to create a 3D rendering of
external and internal geometry, including voids. Then implementing a defect
analysis utilizing computer software)
• Imbibition methods :-Immersion of the porous sample, under vacuum, in a fluid
that preferentially wets the pores.
• Water saturation method (pore volume = total volume of water − volume of
water left after soaking).
• Water evaporation method (pore volume = (weight of saturated sample − weight
of dried sample)/density of water)
• Mercury intrusion porosimetry (several non-mercury intrusion techniques have
been developed due to toxicological concerns, and the fact that mercury tends to
form amalgams with several metals and alloys).

20. APPLICATION
• Porosity is used in multiple fields
including pharmaceutics, ceramics,metallurgy, materials, man
ufacturing, earth sciences, soil mechanics and engineering.

23. FUSIBILITY
• The fusibility of a material is the ease at which the material
can be fused together or to the temperature or amount of
heat required to melt a material. Materials such
as solder require a relatively low melting point so that when
heat is applied to a joint, the solder will melt before the
materials being soldered together melt, i.e. high fusibility. On
the other hand, firebricks used for furnace linings only melt
at very high temperatures and so have low fusibility.
Materials that only melt at very high temperatures are
called refractory materials