the ppt provides complete information regarding sources of rock, texture or surface of rock, minerals of rock and fractures of rock

1. BUILDING
MATERIALS
• SOURCES OF STONES
• MINERALS OF ROCKS
• TEXTURE OR STRUCTURE OF ROCK
• FRACTURE OF ROCKS.

2. SOURCES OF STONES
• All stones are obtained from rocks.
• A rock represents definite portion
on earth’s surface
• It is not homogenious { no uniform
composition}
• If a rock contain one mineral it is
known as monolithic rock ex - the
quartz sand, chemically pure
gypsum.
• If a rock contains several minerals
it is known as polymineralic rock.
Ex- basalt , granite
CHEMICALLY PURE GYPSUM ( MONOLITHIC)
BASALT ( POLYMINERALIC)

3. MINERALS OF ROCK
A MINERAL INDICATE A SUBSTANCE HAVING DEFINITE CHEMICAL
COMPOSITION AND MOLECULAR STRUCTURE.
IT IS FORMED BY NATURAL INORGANIC PROCESS, SUCH MINERALS COMBINE
AND FORM ROCK OF VARIOUS TYPES.
THE PROPERTIES OF ROCK ARE THEN GOVERNED BY THE PROPERTIES OF
MINERALS PRESENT IN IT.

4. TEXTURE AND
STRUCTURE OF ROCK

5.  COMPACT CRYSTALLINE- the fine grains or particles are held
together in a compact crystalline form. EX- marbles, quartite
 CONGLOMERATE- the grains are round and of different sizes.
They are committed by some binding material. EX – quartz or
feldspar.
Fine particles are held together in
compact crystalline form.
grains are round are of varying sizes

6.  FOLIATED- in this type of texture, the arrangement of minerals is in the form of parallel layers. EX- gneiss,
slate
 GLASSY-it is like a glass without any crystal.
PUMICE
The arrangement of minerals in form
of parallel layers.

7.  GRANULLAR CRYSTALLINE – the crystals are of similar size ,
they can be separated, . But they are held together by
some binding material. EX- sandstone , gneiss.
Crystals of similar size
Held by some binding
material.
 PISOLITIC – the grains are bigger in size
and they are large as peas . EX- pisolitic
limestone.
Large pea size grains

8.  POROUS GRANULAR – the grains are in a form of irregular minute
particles and rock with such texture is not durable.
grains are in a form of irregular
minute particles.
 PORHYRITIC – in this type of texture, the
crystals of one or more of minerals are
large and predominant.
One or more minerals are
largely predominant

9.  VESICULAR- the rexture is indicate by small irregular cavities on
rock.
Small irregular cavities on
rock surface.

10. FRACTURE OF A ROCK
The type of surface obtained, when
a rock is broken indicates its
fracture.
For rock with cleavage ( cleavage
refers to the way , some minerals
break along certain lines of
weakness in their structure)
The fracture of rock help to
determine its texture.
The fractured surfaces are most
irregular
Rock with cleavage

11. THE DIFFERENT TYPES OF FRACTURES
 CONCHOIDAL- such fractures present a set of
concentric rings. EX- quartz , flint. And it
respond to glassy texture.
Concentric rings
Glassy texture
 EARTHY- it resembles earth. EX chalk
Resembles earth

12.  EVEN- the fracture surface is more or less plane . Such fractures
denotes crystalline texture.
Plane surface
Crystalline texture
 FIBROUS- the fracture surface is in the
form of fibres as in the case of abestoes
Fibrous surface

13.  HACKLY- it indicates rough and broken surfaces with sharp
edges.
Rough broken
surfaces
Sharp edges
 UNEVEN - the fracture surface is rough due to
minute elevations and depressions . Such
fracture indicates granular texture. The surface is rough
due to minute
elevation and
depression.