DECORATIVE STONES (FACING/POLISHING)
Decorative stones, a testament to nature's artistry, have been used for centuries to enhance the
aesthetic appeal of buildings, homes, and public spaces. Their unique textures, colors, and patterns
add a touch of luxury and sophistication to any environment. From the classic elegance of marble to
the rugged charm of granite, decorative stones offer a diverse range of options to suit various design
styles and preferences.
Types of Decorative Stones
Marble: Renowned for its luxurious appearance and smooth texture, marble is a popular choice for
flooring, countertops, and decorative elements. Its ability to be polished to a high sheen and its wide
range of colors, including white, black, pink, and green, make it a versatile material.
Granite: Known for its durability and resistance to scratching, granite is a popular choice for kitchen
countertops and flooring. Its natural patterns and colors, ranging from dark gray to light pink, add a
touch of elegance to any space.
Limestone: With its soft, earthy tones and porous texture, limestone is often used for flooring, wall
cladding, and landscaping. Its natural variations and ability to absorb light create a warm and inviting
atmosphere.
Travertine: A type of limestone with a distinctive, porous surface, travertine is commonly used for
flooring, countertops, and wall cladding. Its natural holes and pits can be filled with a resin to create a
smooth finish or left unfilled for a more rustic look.
Slate: A fine-grained metamorphic rock with a subtle sheen, slate is often used for flooring, roofing,
and wall cladding. Its natural colors, including gray, green, and purple, add a touch of sophistication
to any space.
Quartzite: A metamorphic rock with a hard, crystalline structure, quartzite is highly resistant to
scratching and staining. Its natural colors and patterns, ranging from white to pink and green, make it
a popular choice for countertops and flooring.
Facing and Polishing Methods
The appearance and durability of decorative stones can be enhanced through various facing and
polishing methods. These methods involve shaping, finishing, and smoothing the stone surface to
achieve the desired aesthetic and functional properties.
Honed Finish: This finish provides a matte or satin appearance by removing the surface layer of the
stone. It is often used for flooring and countertops to reduce glare and create a more natural look.
Polished Finish: This finish involves using abrasive materials to create a smooth, reflective surface.
Polished stones are commonly used for countertops, flooring, and decorative elements.
Flamed Finish: This finish creates a rough, textured surface by applying a torch to the stone surface. It
is often used for outdoor applications to improve slip resistance.
Bushhammered Finish: This finish creates a textured surface with small, uniform indentations. It is
often used for flooring and outdoor applications to improve slip resistance.
Leather Finish: This finish creates a slightly textured surface with a soft, velvety feel. It is often used
for flooring and countertops to add a touch of luxury.
Sandblasted Finish: This finish creates a uniform, matte surface by blasting the stone with sand. It is
often used for outdoor applications to improve slip resistance and weathering resistance.
Acid Etching: This finish creates a textured surface by applying acid to the stone surface. It is often
used for flooring and countertops to enhance the natural color and texture of the stone.
The choice of facing and polishing method depends on the type of stone, the desired aesthetic, and the
intended use of the material. By carefully selecting the appropriate method, it is possible to create
stunning and durable decorative stone surfaces that will enhance the beauty and value of any space.
ROCKS AS CONSTRUCTION MATERIAL
Rocks as concrete aggregate:
Concrete is made by mixing fine aggregate, coarse aggregate, cement and water. The
raw material for making cement is also obtained by rocks. Aggregates are used in concrete for
very specific purposes. The use of coarse and fine aggregates in concrete provides significant
economic benefits for the final cost of concrete in place. Aggregates typically make up about
60 to 75% of the volume of a concrete mixture, and as they are the least expensive of the
materials used in concrete, the economic impact is measurable. Commonly, rocks like
limestone, granite, trap rock, sandstone, quartzite, dolomite, volcanic cinder and
scoria, marble, slate are used as concrete aggregate.
Rocks as railway ballast:
Railway Ballast is the foundation of railway track and provide just below the sleepers.
The loads from the wheels of trains ultimately come on the ballast through rails and sleepers.
The stone to be used as railway ballast should be hard, tough nonporous and should not
decompose when exposed to air and light. Igneous rocks like granite and metamorphic rock
like are the excellent ballast materials.
Functions of Ballast:
a) To provide firm and level bed for the sleepers to rest on
b) To allow for maintaining correct track level without disturbing the rail road bed
c) To drain off the water quickly and to keep the sleepers in dry conditions
d) To discourage the growth of vegetation
e) To protect the surface of formation and to form an elastic bed
f) To hold the sleepers in position during the passage of trains
g) To transmit and distribute the loads from the sleepers to the formation
h) To provide lateral stability to the track as a whole
Types of Railway Ballast:
Sand ballast: Sand ballast is used primarily for cast iron (C I) pots. It is also used with
wooden and steel trough sleepers in areas where traffic density is very low. Coarse sand is
preferred in comparison to fine sand. It has good drainage properties, but has the drawback of
blowing off because of being light. It also causes excessive wear of the rail top and the
moving parts of the rolling stock.
Moorum ballast: The decomposition of laterite results in the formation of moorum. It is red,
and sometimes yellow, in colour. The moorum ballast is normally used as the initial ballast in
new constructions and also as sub-ballast. As it prevents water from percolating into the
formation, it is also used as a blanketing material for black cotton soil.
Coal ash or cinder: This type of ballast is normally used in yards and sidings or as the initial
ballast in new constructions since it is very cheap and easily available. It is harmful for steel
sleepers and fittings because of its corrosive action.
Broken stone ballast: This type of ballast is used the most on Indian Railways. Good stone
ballast is generally procured from hard stones such as granite, quartzite, and hard trap. The
quality of stone should be non-porous and nor it should not flake off due to the vagaries of
weather. Good quality hard stone is normally used for high-speed tracks. This type of ballast
works out to be economical in the long run.
Rocks as roofing material:
Naturally occurring rocks, which are sufficiently consolidated to enable them to be
cut, shaped or split into blocks or slabs are used in roofing. Slate, limestone, and Sandstone
are common types of rocks used in roofing.
Roofing is required for:
(a) Providing structural support to place,
(b) Controlling water ingress, air and heat flow, and
(c) Providing protection to beneath surface.
Rocks as flooring tile:
Flooring is the general term for a permanent covering of a floor. Floor tile should
possess: Adequate strength and stability, adequate moist resistance, adequate fire resistance,
Sound insulation and adequate thermal insulation properties. Stone flooring is a type of floor
covering carved out from natural solid rock. Granite, Marble, Slate, sandstone and limestone
are used as flooring tile. Natural rocks show natural colour variation and easily gets polished.
Marble is very durable, like many other stones, it has a strong resistance to cracking, chipping
and can withstand large pressures if laid on an even surface.
Slate with Quartz in its composition, is dense and highly versatile.
Granite is the hardest of all flooring stones. It is found in endless variety of rich colours. It
has a very dense grain, making it virtually impervious. If polished, granite will resist
scratching and etching.
Sandstone is made up of loose grains of quartz sand that are rough in texture. It is an
extremely hard and tough material, very porous stone; hence it must be thoroughly sealed
when used as flooring.
Rock as cladding stone:
Cladding is the application of one material over another to provide a skin or layer.
Stone cladding is a thin layer of real or simulated stone applied to a building. Granite, marble,
and limestone, have been preferred materials for cladding. River pebbles are also applied as
cladding stone.
Rock as foundation stone:
Foundation is the element of an architectural structure which connects it to the
ground, and transfers loads from the structure to the ground. Rock foundations are always
preferred because rocks offer a number of advantages compare with soil in terms of stability
and durability. Moreover the rocks are strong, durable and economical to use. Even the
weakest rock is better in strength and reliability compared to good soils. Rocks such as
limestone, granite, sandstone, shale and hard solid chalk have a high bearing capacity which
is extensively used for foundation.
