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| Sandstone |
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| Sandstone |
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A sedimentary rock consisting
of cemented grains of
quartz, Sandstone is actually
named after the sand-sized
grains of the quartz.
Commonly found in gray,
buff, red or brown colors,
Sandstone is formed deep
within the ground under
great amount of heat and
pressure, which transforms
small grains into a tough
rock with tightly packed
minerals.
The
cementing material in
sandstone is usually calcium
carbonate, silica or iron
oxide. As there are plenty
of varieties of Sandstone
available in the market,
they are differentiated
on the basis of their
variations in color, hardness
and texture, which in
turn depends on the cementing
material. Those which
contain iron oxide are
red to reddish brown in
color, while those with
silica or calcite as the
binding material will
be light in color, usually
pale yellow, buff, or
white. And green Sandstone
in addition to sand and
glauconite, often contains
fossil shells and iron
oxides.
A
common mineral found in
the earth's crust, Sandstone
is available in large
quantities in association
with most other sedimentary
rocks. Sandstone can be
crushed to form loose
sand grains, which can
be then used in construction
and in other industries
as sand. Due to the variety
of colors and textures
sandstone is available
in, it enjoys a place
in the semi-precious stone
market also. It is also
used extensively in carvings
and cut into spheres or
oval forms.
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| Fancy Sapphire |
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| Purple
& Lavender |
Green |
Orange |
Bi
Color |
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Sapphires are extremely
beautiful and affordable.
They are found in all possible
colors except for red. When
talking about Sapphires
people generally refer to
the Blue colored Sapphires.
The other widely varying
colors of Sapphires are
referred to as Fancy Sapphires.
The most popular colors
of Fancy Sapphires include:
pink, purple, lavender,
white, yellow, orange, green,
bi-color, tri-color and
a mixed color stone, which
has a number of colors in
it.
Beautiful
Blue Sapphires and multicolored
Fancy Sapphires have long
been found in Sri Lanka.
However today Madagascar
has actually out-stripped
Sri Lanka in terms of volume.
Yellow and gold sapphires
are mainly sourced from
Australia, Thailand, Sri
Lanka and Tanzania. Green
Sapphires are found in Australia
and Thailand, whereas Violet
Sapphires tend to undergo
a color change, especially
when viewed under daylight.
Though these sapphires with
a color change are not very
well known they can be quite
magnificent when set in
gold.
Though
Sri Lanka provides a large
portion of the world’s
Blue Sapphires, Australia
and Africa are the world’s
largest suppliers of the
same. Sapphires from the
island of Sri Lanka are
also known as “Ceylon
Sapphires”. Exceptional
Blue Sapphires are also
sourced from Cambodia and
Pailin. Burma too is known
for their high quality supply
of this stone.
The
most famous mining area
for Fancy Sapphires is Sri
Lanka. Here the pink-orange
to red-orange variety of
the gemstone also called
Padparadsha Sapphire or
“lotus blossom”
is available. These are
the most expensive of all
the Fancy Sapphires and
jewellery made with this
stone is very popular. The
popularity of Sapphires
is mainly due to its easy
availability in many different
shapes, sizes and colors.
Thus offering a great variety
to gemstone lovers. Breakage
of Sapphires rarely occurs
due to the fact that the
hardness of Sapphires is
just below that of Diamonds,
thus making it one of the
toughest stones after diamonds.
As
these gemstones occur in
a variety of shapes, colors
and sizes, the intensity,
uniformity and purity of
color, the cut of the stone
and the buyer’s preference
are the most important factors
in determining the value
of these stones.
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| Serandite |
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| Serandite |
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Named after a mineral collector
of West Africa in 1931,
Serandite is the main reason
that Mont Saint Hilaire
in Quebec, Canada is a world
famous collecting site today.
Good quality Serandite available
in the market today all
come from this locality.
The color ranges from pale
pink to salmon-red and rose-red
with a silky luster, which
is very distinctive for
this stone.
Today
small amounts of Serandite
are found on the island
of Rouma, Los Archipelago,
Guinea, as well as at the
Gem Mine, San Benito County,
California. However the
quality and quantity from
these locations can never
compete with those found
on the famous Mont Saint
Hilaire site.
Composed
of Oxygen, Silicon, Manganese,
Sodium, Calcium and Hydrogen
(Na(Mn++,Ca)2Si3O8(OH),
Serandite ranks 4.5 on Moh’s
Scale of Hardness and has
a Specific Gravity of 3.2
- 3.4. The manganese ions
present cause the salmon
pink coloration of Serandite.
Occurring
in prismatic crystals as
well as in massive, compact
forms, Serandite is found
associated with other minerals
such as Calcite, Analcime,
Argirine, Vesuvianite and
Grossular Garnet along with
other extremely rare minerals
found at Mont Saint Hilaire.
The best-known association
is the one of pink colored
elongated Serandite with
rounded snow-white Analcime
crystals. Specimens of this
association are really treasured
by collectors. Serandite
crystals with nice color
and luster are also cut
into attractive gemstones.
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| Smithsonite |
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| Smithsonite |
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Smithsonite is the new name
for Calamine. It was renamed
after the founder of the Smithsonian
Institution, James Smithson
in 1832. The feature that
sets it apart from the other
gemstones is the fact that
It has a very unusual luster,
just like the glow of the
melted wax under the candle
flame.
A
Zinc Carbonate, Smithsonite
is also known for its great
color variations. This is
due to the fact that Zinc
is often replaced by other
minerals, causing the color
to vary. Addition of Copper
renders the stone green
to blue, cobalt results
in a pink to purple color,
whereas Cadmium is the reason
for the yellow color of
the Smithsonite stone. Although
the most common are apple
green to blue green colors,
the lavender color stone
is the most sought after.
Other colors available are
white, yellow, tan, brown,
peach, red, blue and colorless.
Smithsonite
has various crystal habits,
which include rounded rhombohedrons,
scalenohedrons and a fascinating
form called "botryoidal".
These radiating fibrous
crystals appear like grapelike
clusters. As Zinc is the
main element in its chemical
composition, Smithsonite
was used as the principal
source of Zinc till the
1880s. Today however it
is being used to a much
lesser degree in the advent
of new alternating processes
to form zinc.
Formed
in dry climates as a weathering
product of Sulfide Zinc
ores, the major sources
of this stone include Namibia,
Tsumeb and the Broken Hill
Mine in Zambia. Other locations
in South America and Europe
and the Kelly Mine in Magdalena,
New Mexico also produces
some fine specimens.
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| Sphene |
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| Sphene |
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Named after the Greek word
for wedge, due to their typical
wedge shaped crystal forming
habit, Sphene makes for the
most stunningly brilliant,
fiery gem. Sphene is also
alternatively called Titanite
due to its titanium content.
One of the world’s rarest
and newest gems, Sphene has
the ability to break a beam
of light into all the spectral
colors. Thus the stone can
change colors according to
the angle at which you are
looking at it from. Sphene
is predominantly green or
yellowish-green, though occasionally
it is found in pink, black
or brown and every color of
the rainbow mixed.
Formed
from Calcium Titanium Silicate
(CaTiSiO5), Sphene has a Refractive
Index of 1.84 - 2.11 and a
Specific Gravity of 3.3 -
3.6. With a Hardness of 5
- 5.5 on the Moh’s Scale
of Hardness, Shene is relatively
brittle, thus care should
be taken when set in rings.
However due to its unique
color shades it is ideal for
earrings and pendants.
Sphene
is found worldwide in Mexico,
Brazil, Canada, USA, Sri Lanka,
Madagascar, Switzerland, Italy,
Pakistan and Russia. The body
color, the degree of inclusions
and the cutting styles of
the gem determines the dispersion
of colors in the stone which
in turn determines the value
of the Sphene. Also clean
stones larger than a few carats
are rare.
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| Spessartite Garnet |
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| Spessartite
Garnet |
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Spessartine Garnets or Spessartite
are also referred to as ‘root
beer’ colored Garnets
as they are found as orange
to red orange stones. Its
name is derived from its place
of discovery - Spessart in
Germany and is mined primarily
in Brazil, Madagascar and
Sri Lanka today.
A
popular stone since the Bronze
Age, Garnets are believed
to contain both protective
and destructive elements.
It is also believed to be
the gemstone that guided Noah’s
ark to salvation during the
Great Flood, according to
both the Christian and Jewish
mythologies.
Due
to its association with a
rich red color, the name ‘Garnet’
is believed to have been derived
from the red ‘Garnet
colored’ seeds of the
‘pomegranate’.
And though it is associated
with the red color, it is
actually found in a range
of colors such as reds, oranges,
greens and the color change
varieties.
Garnets
are a group of 7 related minerals
with slight variations in
their chemical compositions.
The major types are Almandine,
Pyrope, Spessartine, Grossular,
Andradite, Rhodolite and Malaia.
Found in a variety of locations
such as Kenya, Sri Lanka,
Thailand, Brazil, India and
Arizona (USA), the main supply
today comes from Africa. .
As
Garnets are available in a
range of different colors,
color plays an important role
in the evaluation of Garnets.
The color of the stone should
be intense and uniform and
should suit the wearer’s
personality. Size too is an
important determinant of its
value.
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| Blue Sapphire |
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| Ceylon |
The modern day word
Sapphire is derived
from the ancient Latin
word ‘Sapphirus
‘. The island
of Sri Lanka (previously
known as Serendib) holds
the earliest records
for the mining of sapphires.
Sapphires are seen in
all spectrums of color,
except for red. But
when people refer to
Sapphires, they generally
mean blue colored sapphires,
whereas the other color
Sapphires are referred
to as fancy Sapphires.
Believed to contain
the power of wisdom,
ancient people believed
in the power this stone
had on the wearer when
faced with challenges
so as to enable them
find the correct solution.
Sri Lanka provides a
large portion of the
world’s supply
of blue Sapphires. And
the stones from this
island are called ‘Ceylon’
sapphires, after the
name of the island.
Besides Australia and
Africa, which are the
world’s largest
supplier of blue sapphires,
they are also found
in Pailin, Cambodia
and Burma.
With
a hardness that is just
below that of diamonds,
Sapphires is one of
the toughest stones
available in the market.
With no cleavage and
breakage occurring,
sapphires ensure enduring
popularity. They also
come in many different
shapes and sizes, thus
providing a great variety
to gem lovers.
Intense
dark blue colored sapphires
are the most popular
in the market; however
very fine sapphires
are extremely rare.
Sri Lanka, Cambodia
and Burma produce fine
pure blue colored sapphires,
though the Cambodian
stones are slightly
darker. And the Australian
sapphires tend to have
a green overtone and
concentric hexagonal
bands. Though midnight
blue sapphires have
been looked down upon
traditionally, today
it is gaining popularity
especially for setting
into sapphire earrings.
Purity, uniformity and
intensity of color are
the most important factors
to be considered when
buying a blue sapphire.
The finer stones should
not contain any secondary
colors, as the beauty
of this precious gemstone
will lessen. The overall
beauty also depends
on the cut, so this
characteristic too should
be taken into consideration.
While fine blue sapphires
maintain their color
in any light setting,
the dark blue variety
appear as black under
low light settings.
Blue
colored Sapphire jewellery
is one of the most sought
after jewellery especially
in rings, earrings,
pendants and necklaces,
which add to the beauty
of any collection.
| Padparadsha Sapphire |
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| Padparadsha
Sapphire |
With its name
derived from the
Latin word ' Sapphirus
', the earliest
mention of Sapphires
are recorded in
the island of
Serendib (now
known as Sri Lanka).
Believed to contain
the power of wisdom,
ancient people
believed in the
power this stone
had on the wearer
when faced with
challenges so
as to enable them
find the correct
solution.
Available
in all spectrum
of colors except
for red, when
people generally
refer to sapphires
it is understood
that they mean
blue sapphires,
while the remaining
colored sapphires
are known as Fancy
Sapphires.
With
a hardness that
is just below
that of diamonds,
Sapphires is one
of the toughest
stones available
in the market.
With no cleavage
and breakage occurring,
sapphires ensure
enduring popularity.
They also come
in many different
shapes and sizes,
thus providing
a great variety
to gem lovers
and also making
it ideal for all
kinds of jewellery
settings.
Famous
for mining Fancy
Sapphires Sri
Lanka is also
known for their
'Padparadsha Sapphires'.
These pink-orange
to red-orange
colored gemstone,
has its name derived
from the native
phrase meaning
'lotus blossom'.
The most expensive
of all fancy sapphires,
the Padparadsha
gemstone has become
extremely popular
in recent times
especially in
its usage in jewellery.
Color
intensity is one
of the most important
characteristics
involved in determining
the value of these
gemstones. An
expensive stone,
the Padparadsha
Sapphire should
display purity,
intensity and
uniformity of
color. The cut
is also an important
factor to be considered
while evaluating
this gemstone.
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| Sillimanite |
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| Sillimanite |
Named
after the American chemist
and minerologist, Professor
Benjamin Silliman (1779
– 1824), Sillimanite
occurs in brown, dark
brown, pale green and
white colors. Formed
from Aluminum Silicate
(Al2SiO5) in mostly
silky, fibrous masses,
it is also called Fibrolite
at times.
Though
found in several locations
worldwide such as: Brazil,
Central Europe, Myanmar,
Sri Lanka, Czech Republic,
Italy, India, Germany
and Idaho (USA); pure
specimens of Sillimanite
are not common. Typically
found scattered in layers
of metamorphic rocks
put under great pressure
and high temperature,
Sillimanite is commonly
found in volcanic or
hot spring areas. As
it is scattered within
rocks, Sillimanite can
only be detected with
some effort and a good
microscope. The best
indicators of Sillimanite
in the field are its
color, brittleness,
crystal habit and hardness
(if it is not fibrous).
With
a hardness of 7.5 on
the Moh’s Scale
and a Specific Gravity
of 3.2, the fibrous
crystal form is an interesting
mineral form and is
collected as a mineral
specimen. The glassy
crystal is used as a
gemstone and in ornamental
carvings.
Sillimanite
crystals also display
a cat’s eye effect,
which is caused due
to the inclusions of
fine, slender parallel
fibers, which reflect
light in a single slice
along the center of
the crystals. These
stones also exhibit
a special characteristic
that resembles the eye
of a cat when polished
as cabochons.
| Sodalite |
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| Sodalite |
Sodalite
was discovered in 1891
at a deposit near Bancroft,
Ontario by Frank Adams,
while he was studying
the geology of the Haliburton-Hastings
area for the ‘Geological
Survey of Canada’.
A mineral possessing
a beautiful blue color,
Sodalite is used in
carvings and some jewellery
pieces and is quite
popular in the semi-precious
stone market.
Sodalite
is the most common mineral
of the Sodalite mineral
group, which has minerals
with related chemistry
and similar isometric
structures. A sub-group
within a group, the
members of the Sodalite
group are a part of
a larger group called
the Feldspathoids. The
Feldspathoids are low
silica igneous minerals.
Besides Sodalite, the
remaining members of
the Sodalite Group include
Hauyne, Nosean, Lazurite
and Hackmanite.
Composed
of Sodium Aluminum Silicate
Chloride (Na4Al3(SiO4)3Cl),
Sodalite has a hardness
of 5.5 - 6.0 on the
Moh’s Scale and
a Specific Gravity of
2.1 - 2.3. Named after
the sodium content found
in the mineral, Sodalite
occurs in colors ranging
from royal blue to light
blue as well as white.
Sodalite crystals are
vitreous and transparent
to translucent and commonly
occur in a massive form.
However these specimens
can appear opaque.
Relatively
rare, there are only
three large deposits
of Sodalite known worldwide:
Bancroft (Ontario),
Ice River area (British
Columbia) and Litchfield,
Maine (USA). Small amounts
of Sodalite are also
found in Italy and Brazil.
Besides having a beautiful
blue color Sodalite
is believed to aid in
cooling and drawing
infections, burns, sinus
inflammations and opening
the throat chakra. It
is also believed to
help spiritually by
aiding courage and endurance
and helps release the
subconscious of fears
and guilt.
| Spinel |
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| Noble
Red Spinel |
Fancy
Color Spinel |
The
red brilliance of Spinel
has led to great confusion
throughout history,
causing many to mistake
this gemstone for ruby.
In fact, many world
famous ‘rubies’
have actually been found
to be Spinels. For example
the 170 carat Black
Prince’s Ruby
on the British Imperial
State Crown and the
352 carat Timur Ruby
have been recognised
as Spinels by leading
gemologists.
The
confusion between Spinel
and Ruby stems not only
from their similar colors,
but also due to the
close proximity of their
deposits. Burma identified
this variety in 1587
and was the first to
distinguish Spinels
as a distinctive gemstone
type. However other
countries around this
time still referred
to Spinels as ‘Balas
Ruby’. Though
exceptional stones are
found in Sri Lanka and
Russia, the finest Spinels
are currently mined
in Burma.
Spinels
occur in various different
colors and the red,
orange and vibrant pink
color varieties are
the most expensive.
Cobalt Spinels with
its exceptional blue
color resembling fine
sapphires have also
been discovered in Sri
Lanka and are very highly
priced. Large Spinels
with sizes greater than
5 carats are found occasionally,
however the stones seen
in today’s market
are less than 5 carats
in weight.
With a hardness of 8
on the Moh’s Scale,
high refractive index
and no cleavage Spinels
are excellent stones
to set into jewellery,
such as rings, necklaces,
earrings and other forms,
which will add value
to any collection.
The
color intensity of the
stone is very important
while evaluating the
value of Spinel. The
stones should be intensely
colored without any
brown tones. Clarity
too is an important
factor with clean Spinels
fetching higher value.
The cut of the stone
too is important while
evaluating these stones,
as well-cut stones are
quite spectacular.
| Star Garnet |
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| Star
Garnet |
History
has it that the Garnet
dates back to the Bronze
Age (more than 5,000
years ago), when it
was a very popular gemstone.
According to Christian
and Jewish mythologies,
when God's wrath clouded
the earth with thunderous
storms and endless rain
during the Great Flood,
a radiant red Garnet
guided the way for Noah,
ultimately leading his
ark to salvation.
Garnets
are believed to contain
both protective and
destructive elements.
The Crusaders set Garnets
into their body armor,
believing the protective
power of the stones
would lead them to safety.
Conversely, some Asian
cultures added Garnets
to bullets, believing
its destructive power
would greatly amplify
the enormity of a wound.
The
nomenclature "Garnet"
is believed to have
derived from "pomegranate"
with its red, "Garnet
colored" seeds. While
the name Garnet has
long been associated
with a rich red color,
the gemstone actually
comes in a much wider
array of color variations
including: reds, oranges,
greens and color change.
The
Almandine Garnets (also
known as “Almandite”)
are the most common
variety of Garnets,
and those displaying
the star are not at
all common. Available
in deep reds, Almandine
Star Garnets are found
in Africa.
The
various types of Garnets
are comprised of different
chemical components
but all share a Refractive
Index of 1.72 1.94,
Specific Gravity of
3.40 4.30 and Hardness
of 6.5 7.5 on the Moh’s
Scale. Garnets are found
in a variety of locations
around the world including:
Kenya, Sri Lanka, Thailand,
Brazil, India &
Arizona (USA). They
are available in a wide
range of “warm”
tones such as reds,
oranges, yellows and
Burgundies, as well
as greens and some rare
color-change varieties.
Color
is the most important
characteristic when
evaluating Garnets.
And as Garnets display
a wide variety of different
colors it is important
to choose a stone that
matches the wearer’s
personality. The color
must be intense and
uniform with a tone
that is not too light
or too dark. Fine Garnets
should be eye clean
with minimal inclusions
under magnification.
Size also forms an important
element in determining
the cost of the Garnet.
| Color
change Sapphire |
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| Color
change Sapphire |
Sri
Lanka previously known
as ‘the island
of Serendib’ holds
one of the earliest
records for the mining
of Sapphires. The modern
word Sapphire is derived
from the ancient Latin
term "Sapphirus". Ancient
people believed that
the power of wisdom
is contained within
this precious gemstone.
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