Tuesday 23 December 2014
Monday 1 December 2014
Saturday 29 November 2014
Diamond Formation
The glitter of diamonds, the perfection of their facets and their scintillating fire always makes one wonder that how did these
shining beauties come to existence? Diamonds are formed under certain precise
conditions in the deep interiors of the earth. These sparkling fruits of nature
are believed to be more than billions of years old and form under the stable
continental plates. In this post we will unearth the
procedure of diamond formation.
The formation of diamonds takes place under extreme conditions.
Diamonds form mostly in the mantle which is below the surface layer of the
earth at a distance of approximately 150 Kms. When carbon crystals are
subjected to a temperature of 1050° C and a
pressure of 45000-60000 Kilobars, is when the process of diamond formation
begins. These conditions are not present uniformly in the layers of the earth.
These conditions mostly exist under the stable continental plates. These
stable parts are called cratons.
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| CRATONS |
It is a fairly common belief that when a person or an object is
subjected to immense pressure and difficulties they either they crack or come
out victorious. The same is with the diamonds they undergo extreme heat and
pressure in the interiors of the earth
but a slight change in the conditions can lead to formation of graphite.
 |
| GRAPHITE |
There are two types of diamonds – P Type and E Type. P type diamonds
are formed with the help of peridotitic rocks and E type are formed with the
assistance of eclogitic rocks.
Peridotite and eclogite are referred to as source rocks as the diamonds
form in these igneous rocks. These rocks exist under the earth in a molten
state and they continuously emit carbon. The carbon atoms under the immense
heat and pressure of the earth’s interiors start locking with each other. If
the conditions are accurate diamond crystals start forming.
 |
| PERIDOTITE |
Diamonds formed in the mantle are brought up to earth’s surface by
the deep volcanic eruptions. These eruptions break the mantle and bring the
diamonds to the surface. The rocks which transport the diamonds are kimberlite
and lamproite. Kimberlite and lamproite are formed in the molten magma in the
mantle. The magma expands as it heats up
and it passes through a fracture in the crust. While passing through a fracture
it might come in contact with a diamond deposit and carry the diamonds along
with it. The magma then continues to rise and the pressure decreases. With the
decrease in pressure magma is able to travel at a very high speed of about 300
Kms/hour. At this stage some chemicals start to vaporise into carbon dioxide
and water vapour. The speed of magma along with release of gases leads to an
explosion. At this very point kimberlite pipes are formed. These pipes are
where the majority of diamonds are found.
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| KIMBERLITE PIPE |
Any change in vaporisation and the speed of magma can result in
formation of graphite. The kimberlite or lamproite then solidifies creating a
diamond rich deposit. This is what most of the diamond miners hunt for.
Diamonds go through a lot before one sees them glittering in a
store’s display. They undergo extreme heat and pressure and are brought to the
earth by violent eruptions. For years together they trapped there until
unearthed by man. Thereafter, they are cut and polished and that’s when one
sees the real beauty of diamonds. And
that is why it is said, to have an understanding of diamond formation is
extremely important not only from technical aspects but also because so that
one can appreciate this unique process and also how rare are fine gem quality
diamonds.
Friday 31 October 2014
Sunday 5 October 2014
Monday 29 September 2014
Monday 22 September 2014
Saturday 30 August 2014
TECHNIQUES OF METAL DECORATION (PART-2)
In the
previous post of The Jewel Affair some very interesting techniques like
Filigree, Repousse´ & Chasing and Enamelling were discussed in detail. In
the proceeding post, subjects like acid etching, stamping, embossing and engraving
will be dealt with.
Acid
Etching: etching has been derived from a German word for ‘eat’. This technique
literally lets the acid bite into the metal surface to create relief patterns.
In other words it can be described as a technique which uses the concept of
corrosion for metal decoration. The basic idea is to create a design on the
metal and cover the areas which one wants in high relief with acid proof
substance. Thereafter the metal plate is submerged in acid and then the exposed
areas start corroding and creating relief patterns.
The
earliest findings of this techniques dates back to 1500 A.D. The technique was
most widely used for creating armours and art work but today the technique is
more widespread. Nowadays it is also being used as a preliminary step in the
process of enamelling.
The
latest version of acid etching process is Photo Etching. In this process the
metal sheet is firstly covered with photosensitive polymers to avoid any
deforming of the metal because of its exposure to the ultra violet light. Then
with the help of computer aided software patterns are created and transferred
on the metal with the help of UV lights. Then the metal sheet is thoroughly
cleaned and then it is laminated. The laminated piece is put into the photo
tools and again exposed to UV lights. The selected areas of the laminate are
converted into acid proof areas. The sheet is then sprayed with acid and
corrosion takes place. Thereafter, the sheet is cleaned again and the result is
smooth relief patterns.
The
advantage of this method is its low cost of production; it is not a labour-
intensive technique, requires less cleaning and finishing and the precision
achieved is remarkable.
 |
| ACID ETCHING |
Stamping:
it is a procedure in which the metal is pressed between steel dies in a
hydraulic press at very high pressure. This method is ideal for large scale
production and is widely used for manufacturing coins, pendants, earrings and
shanks. On a smaller scale it can be taken up individually with the help of
stamps, hammer and other tools. Here the process is relatively simple when
taken up individually than the other techniques. The only drawback is that the
design options here are limited.
 |
| STAMPED JEWELRY |
 |
| STAMPS |
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| TOOLS FOR STAMPING |
Embossing:
under this technique the metal is usually punched from behind to create relief
work on the other side. Varieties of tools are used to achieve the desired
result. First and foremost the design is traced out on the metal foils or
sheets with the help of a stylus, which is an embossing tool. The design is
then worked around with a couple of more tools to create the relief. The height
of the relief is a matter of personal choice. Finally some pointed tools are
used to refine the design from front and the design is finished with buffing
tools.
 |
| EMBOSSED JEWELRY |
Engraving:
it is an art of carving out designs on metal surfaces. A chisel is usually used
to incise the design, which is also termed as a burin. Chisels come in various
varieties and are used by metal workers on all sorts of metals like copper,
steel, gold and silver. Engraving is used for various purposes like jewelry,
armours, weapons and kitchenware. With technological advancement machines are
created for engraving bigger sheets of metal and sometimes dyes are also used
for engraving designs.
 |
| ENGRAVING |
One
can say that these techniques of metal decoration have revolutionised the way
it was used by the pre-historic man. Owing to these techniques beautiful
artwork started developing. When one looks back, these techniques also give us
important clues about our ancestors and the way development came about in those
times. So, these techniques have not only beautified the world around us but
also show us how we have evolved through these centuries.
*Pictures adopted from Google.
Monday 25 August 2014
Wednesday 30 July 2014
TECHNIQUES OF METAL DECORATION (PART-1)
Development
of human civilisation was heavily dependent on discovery of metals.
Pre-historic man gradually understood the use of metals and started to use them
for various purposes. He started fashioning them into weapons and tools. With
the progress of time he discovered metals like copper, bronze, silver &
gold. He started using these metals for personal adornment and one after the
other advancements were made in the way jewelry was fashioned by him. As a
result, beautiful techniques were developed to decorate metal.
This
post of The Jewel Affair is an effort to explore the journey of how these
techniques evolved over the centuries. Some of the most popular techniques are:
FILIGREE:
it can be defined as an ornamental technique where twisted wires of silver and
gold are joined together to create an open framework. The word filigree is
derived from the Latin word filum
meaning thread. Filigree is also known as telkari-
Anatolian word meaning wire work.
Filigree
is an ancient art which was practised by the Greeks and Etruscans (ancient
Italian Civilisation). This art advanced the most in the period from the 6th
Century B.C- 3rd Century B.C. In the Medieval times it was practised
by the Moors of Spain. Moors were the Medieval Muslim inhabitants who practised
this art to perfection and created exquisite designs. Around 600 A.D the Irish
craftsmen became renowned for the variety they brought about in the art.
Filigree
still exists in India, Mexico and Scandinavian countries. In India the
craftsmen till date retain the patterns of the ancients Greeks. These patterns
are believed to be passed on from the time the Greeks came to settle down in
India. Cuttack in Orissa still showcases traditional filigree work.
Filigree
is of two kinds:
Open:
in open filigree the wirework is an open framework. There is no metal backing
or support.
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| OPEN FILIGREE |
 |
| CLOSED FILIGREE |
REPOUSSE´
& CHASING: This is technique of freehand hammering which uses specific
tools to create relief work. This technique is a combination of two techniques
put together.
Repousse´ is a French word which means to
‘push out’. In this technique the metal is hammered from both front and back to
create a sculptural relief. It is believed to be an ancient technique. Armour plates
decorated with this technique are found which date back to the 3rd
century B.C. Repousse` is of two kinds:
- Eastern Repousse´
- Western Repousse´
The
difference between these two techniques is basically of the tool shapes and the
angle at which the metal is struck. And the most notable difference is of the
height and depth created in the relief. Eastern technique was used by ancient
Egyptians and Greeks and Western technique moreover used in western Europe,
Japan, Thailand and other parts of Asia.
The most
famous examples of Eastern Repousse` are the Gold Mask of Tutankhamun and
Vaphio cups. The biggest sculpture created with this technique is The Statue of
Liberty.
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| GOLD MASK OF PHARAOH TUTANKHAMUN |
 |
| VAPHIO CUPS |
On the other hand, chasing is used only on the
front side of the metal to bring finesse to the design. This is usually a slow
process and there is no loss of metal. The only disadvantage of this process is
that contact of tools with the metal is evident unlike other techniques.
A
repousse` artist uses a working surface which is called the chaser’s surface.
It is made of pitch which is a viscous polymer derived from coal tar, resin and
plaster of Paris. This surface keeps the metal in place while it is hammered.
ENAMELLING:
in this technique coloured powdered glass is used create a transparent coat on
the metal. Powdered glass is fused on to the metal by application of heat, the
glass then melts and flows and is fused to the metal. This is an ancient
technique of decorating jewels and artefacts. The earliest remains of enamelled
artefacts dates back to 13th century B.C. This technique in
modification was used largely by the Egyptians and Romans.
There
are various enamelling techniques which are used, but this post deals with four
most popular techniques:
CHAMPLEVE´:
it is French word meaning ‘raised-field’. This technique blossomed fully in the
12th century and was most popularly practiced in France and Italy.
For Champleve` a slightly thicker metal sheet is used and patterns are
developed by creating a low relief. Basically, the metal is shaved out a bit to
create space for enamel to be filled in. The recessed areas are then filled
with powdered enamels and heated so that the enamel melts. Enamel is built up
in layers so that it reaches the same height as that of the remaining metal.
This technique was used mostly with copper.
 |
| CHAMPLEVE´ |
BASSE-TAILLE:
Basse-Taille literally means low cutting or engraving in French. It is
an
extension of Champleve´ technique and developed to its best in 13th-14th
century. It is slightly different from Champleve`. The basic difference is that
the area which is shaved out, in that area a figure or a design is chased out
and instead of powdered enamels transparent enamels are used. This technique is
used on usually gold or silver. In Basse-Taille the metal shines through the
transparent enamel and adds a beautiful glaze to the enamel. All these factors
in totality give the enamelled object a three dimensional effect.
 |
| BASSE TAILLE |
CLOISONNE´:
the name of this technique is derived from the French word cloison, which literally means a cell. This art was most popular in
the periods between the 6th-12th century in East Roman
Empire and Gaul and Britain. In this technique flattened wires are soldered on
a metal base. The attached wires result in creation of cells or compartments.
These compartments are then filled with powdered enamel. The enamel is then
heated and fused with the metal.
 |
| CLOISONNE´ |
PLIQUE-A´-JOUR:
in French Plique-A´-Jour means ‘letting in daylight’. This technique is similar
to Cloisonné except for the fact that the wirework created does not have any
backing or metal attached to it and transparent enamel is suspended in the
cells of the wirework and then heated. This is used to create a stained glass
effect. Several transparent colored enamels are blended between the wires to
give that delicate water color like appearance.
 |
| PLIQUE-A´-JOUR |
Part-2
of this article will talk about some more interesting techniques like Acid
Etching, Embossing and Stamping.
*Pictures adopted from Google.
Saturday 19 July 2014
Thursday 10 July 2014
Perspective Drawing
The previous post of The Jewel Affair spoke
about technical drawings. The two types of technical drawings commonly used
are:
- Orthographic Representation (Article-6)
- Perspective Drawing
This article is about an introduction to the
perspective drawings and its types. These technical drawings are very
interesting and intricate at the same time. And is the most important link
between the designer and the craftsman. One can use these drawings to provide
the smallest of detail for the designed product.
But, how does one define perspective drawings?
Perspective drawing is a technique which is
used to represent three dimensional images on a two dimensional plane. There
are two main aspects of perspective drawing:
The size of the object seems to diminish
according to the distance.
The tone and colors change as you move farther
from the object.
One of the most important elements of a
perspective drawing is a Horizon Line. This is directly opposite to the
viewer’s eye level.
Types of Perspective Drawing:
One Point Perspective: it is named so because
it uses only one Vanishing Point (vp) to draw an object. The vanishing point is
usually on the horizon line. All parallel lines from the viewer’s angle recede
to the horizon towards the vanishing point.
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| ONE POINT PERSPECTIVE DRAWING |
 |
| EXAMPLE OF ONE POINT PERSPECTIVE |
Two Point Perspective: this type of drawing
uses two Vanishing Points (vp1 and vp2) and the lines are parallel to two
different angles.
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| TWO POINT PERSPECTIVE DRAWING |
 |
| EXAMPLE OF TWO POINT PERSPECTIVE |
Three Point Perspective: as the name suggests
it has three vanishing Points (vp1, vp2 & vp3). In addition to the two
vanishing points the third Vanishing point is added either above or below the
perpendicular, as to how the wall will recede in the ground or soar above. So,
the vanishing point is considered either above or below the ground.
 |
| THREE POINT PERSPECTIVE DRAWING |
 |
| EXAMPLE OF THREE POINT PERSPECTIVE |
Perspective drawings are used on a large scale
by interior designers and architects. Three point perspectives are the most
useful for a jewelry designer.
Technical drawings are the most useful tools in
the hands of a designer and the most vital aid for a craftsman. It is the most crucial
link between the artist and the worker. So, one must practice these drawings
until perfection is arrived at.
Construction of perspective
drawings is a complex and practical process. It is best understood practically
in a class through an expert.
Picture Courtesy: Google Images
Tuesday 8 July 2014
Monday 23 June 2014
Technical Drawings
Article-6
Technical
Drawings
Technical drawings are a means to communicate
fine, detailed information about a piece of designed jewelry which helps in its
construction. It is the link between the designer and the craftsman. With the
help of technical drawing a craftsman is able to determine how the piece will
turn out to be and what methods of manufacturing he has to apply in order to
attain the desired result.
There are two basic categories of technical
drawing:
Orthographic
Representation
Perspective Drawing
In
this post of Jewel Affair only orthographic representation will be covered.
Importance
of Technical Drawings:
When one looks at the basic front view of a
design it can be interpreted in different ways. For example if one looks at a
circle drawn on paper it can be either interpreted to be a sphere or a flat
disc. But if one provides the same circle with a technical view, it
communicates exactly what has been thought of and hence, it avoids unnecessary
confusion.
 |
| IMPORTANCE OF TECHNICAL DRAWINGS |
Orthographic
Representation:
It
is a way of representing a three dimensional object in two dimensions. This is
achieved by creating different views of an object. These views are:-
Top view: this view can be defined as the face
of an object or how the product appears when viewed from top.
Front view: the elevation of the product is
referred to as the front view.
Side view: this view usually shows the left or
the right side of an object.
This helps in replicating the product with
precision and accuracy. To create the orthographic representation actual
dimensions of an object are used.
Construction
of an Orthographic View:
 |
| CONSTRUCTION OF ORTHOGRAPHIC VIEW |
Material
required- pair of set squares, ruler, pencil, eraser and a drawing sheet.
With the help of your set squares draw the ‘x’
and ‘y’ axis. Mark 30 mm on all four quadrants. And then join the marked points
to create a square. What we achieve here is a big square with four small
squares inside. These small squares are called quadrants.
The outlines created are called the projectors
and they are perpendicular to the faces of the object and parallel to each
other.
The quadrants are marked with numbers.
RULE:
Never draw inside the quadrants. Drawing has to
be done on the extended lines of quadrants 2, 3, and 4.
In quadrant 1 we draw an angle of 45° and extend
the line outside the big square. Top view is represented by extension of
quadrant 2. Front view by quadrant 3 and side view by quadrant 4.
Always take the measurements in millimeters and
show the measurements always in the front and side views.
This is the basic guideline of an orthographic
view.
Further illustrated here is the view of a flat
band.
 |
| ORTHOGRAPHIC VIEW OF A FLAT BAND |
Construction: Material required- pair of set
squares, ruler, pencil, eraser, a drawing sheet and a compass.
Draw the basic guideline as explained above.
Measure the ring size or the finger size, the
thickness of the shank the width of the band and outer size (ring size +
thickness of the shank)
Extend the lines of quadrant 2 horizontally and
vertically. Mark the width of the band on the ‘y’ axis (vertical) and the outer
size on the ‘x’ axis (horizontal). Now, with the help of the set squares draw a
rectangle with these measurements. This is the top view of the band.
Extend the lines of quadrant 2 corresponding to
the outer size vertically downwards to quadrant 3. Mark the outer size on ‘x’
and ‘y’ axis and draw a square of this size. Using a compass to draw a circle
of 9 mm radius, touching the four corners of the square. Also draw a smaller
circle of 8 mm radius inside the 9 mm circle. This represents the elevation or
the front view of the flat band.
To create the side view lines have to be
extended both from top and front view.
From the top view extend the line which
corresponds to the width horizontally until it meets the extended angle line
created in quadrant one. From the point where it meets the angle line, extend
the line vertically downwards.
From the front view extend lines corresponding
to the outer width and lines corresponding to ring size horizontally towards
quadrant 4. When the lines from both the front and top view meet the side view
is automatically created.
One could also create cross sections in the
front and side views to facilitate clear understanding of the design.
For this flat band, cross section of the side
view is presented. To draw the same extend the lines of the side view
vertically downwards. Using the same measurements create the same view as
above. The only difference will be that the cross section will reveal the
thickness of the shank.
Tip: try to imagine the flat band in
your head and how it will look when it is cut.
Imagination
is a powerful tool for a designer. One has to give it a right direction to
achieve desired results. Similarly orthographic view is what will give one the
direction to accomplish the pre-determined idea.
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