A.S. NeneProfessor of Civil Engineering (Retd)

VNIT Nagpur

Uses of Stones

Making sculptures

Building blocks for construction.

Sources of building stones

From hills From underground mines Riverbanks and forests

The stones obtained from barren land,

graveyard or those embedded

in ground are unsuitable.

Stones obtained from sites unsuitable

for habitation are also unsuitable.

Ref. Kashyapashilpa

Classification of stones

By Color

White

Milk, Jaya flower, Buffalo’s eye, Conch, Moon, Pearl Crystal et

Red

Indragop (insect), Rabbit’s blood or Pomegranate Flower etc.

Yellow Flowers like, Mallika or Korandi

Black

Kajal (eye ointment), Blue lotus, Wasp, Vest part of peacock, black gram etc

Ref. Kashyapashilpa

Stones of first or third category are unsuitable

By Age

Child Sound produced as un-burnt

bricks, long or flat in shape as

a leaf

Young Long ringing sound like bell,

soft in touch, with good smell,

without pores

Old Non-ringing sound, highly

porous, highly weathered

Ref. Mayamat

By Gender

Male Big, rounded, which produces

sparks when hit with chisel- Suitable

for columns

Female Medium size, soft in touch, broad at

base –Suitable for beams

Neutral Small, broad at top, not sounding-

Suitable as aggregates

Ref. Vishnudharmottar Purana

Defects in building stones

Lines • curvilinear (as thread),

• straight (as sun rays)

• parallel (as rains)

Spots size. lemon fruit (15-20 mm),

grape size (5-10 mm),

less than 5 mm.

Ref. Mayamat

Detection Of Defects In Rocks

Microscopic defects in stones , which were

invisible to eyes, were detected by applying

some herbal paints so that the defects were

clearly visible.

Stone softening

The Incas employed certain methods to make

their stones fit perfectly. They knew a plant whose

juices rendered the surface of a block so soft that

the intricate fittings were accomplished.

Stone with 14 angles

Stone wall at Cuzco (Peru)

Adamantine glues

A bonding agent was very essential for fixing idols,

In wall construction, when cement and other modern

materials were unknown.

Even now, these glues were known as Astabandha,

are prepared in temple premises for fixing or re-

fixing images of gods.

Breaking of stone blocksHeating: The stone block is heated by make a

pyre of wooden logs of Palash or Tinduk trees.

The heating is continued till the color of wooden

logs becomes bright red or orange. Cooling: The fire is moved to adjacent area of

rock surface. The preheated surface is cooled down

quickly by pouring certain types of liquids listed

below.

•Solution of quick lime in cold water

•Solution prepared by mixing buttermilk with rice paste, ripe

berries.

•Solution prepared by boiling Neem leaves and some tree

barks.

Ref. Brihat Samhita

Tempering or hardening of tools

1. heating the tool in fire until it becomes red hot. 2. application of paste of certain materials and / or dipping the red-hot tool in a specific solution. 1. sharpening the tools.

The Paste / solution used in step 2

Paste made of • excreta of pigeon and rat, • powder of horns of a buffalo • milk extract of a plant (Mandar) Solution of buttermilk and ash of banana plant

Ref. Brihat Samhita

Suranga –A water tunnelSuranga is a tunnels bored horizontally on the slopes of hills to get clean drinking quality water. Found in many parts of Dakshina Kannada district of Karnataka and Kasaragod district of Kerala ‘Quanat’ is a similar structure used in Iran and Iraq

QuanatSuranga

Building Stones

The Indus valley civilization shows the use of

• Tertiary limestone,

•Sandstones

•Mesozoic steatite.

Marble cutting achieved a remarkable level of

sophistication, with the intricate undercutting in

the 11th and 12th century temples at Mt-Abu

Conclusions

Different types of stones were used in different time spans

Selection of the stones by texture and strength and absence of micro cracks,.

Ancient knowledge is applicable even in modern times.

More information on defects of rock was provided in ancient texts.

References

1.Kashyapashilpa

2.Mayamat

3.Shilpratna

4.Vishnu Purana

5.Shilparatnakar

6.Brihat Samhita