Regression analysis: Simple Linear Regression Multiple Linear Regression
Birthstone Jewellery
1. BIRTHSTONE JEWELLERY
Instead of buying the most expensive ring, attach the most beautiful gemstone to the
engagement ring, adding something extra that will make your ring memorable forever. Or
give someone a ring as a gift to remember forever.You should consider getting their
birthstone! Birthstones are traditionally given as a gift to someone. Depending on the month
in which the stone owner is born. Different countries actually have had different lists in the
past, which is why jewellery sellers are confused as to what is actually a list of "standard"
birthstones.
In 1912, in an effort to standardise the birthstone, the (American) National Association of
Jewelers officially adopted a list, now known as the modern birthstone. Here are the
following stones that you can consider to set in your precious engagement ring.The
birthstone for January is garnet. Available in Brazil, Russia, East Africa and India, the best
garnet is found in Sri Lanka. Garnet is a very popular gem. It is used for jewellery such as
rings, necklaces and bracelets. Garnet can be red (which is the most popular), pink, green,
grey and yellow.Amethyst is the birthstone of February. Amethyst is probably the thirteenth
most popular stone in the world. Amethyst is purple quartz. When heated, the amethyst may
turn yellow which produces citrine. Amethyst is found in Geode, most of which is found in
Brazil. The deep purple colour of amethyst has been known for centuries as the colour of
royalty and even part of the British Crown Jewels.Aquamarine is the birthstone of March.
Aquamarine is actually sea water. When you look at the shimmering sides of the aquamarine
you will hear almost roaring waves. It is said that its genius even rivals diamonds. Gemstone
quality aquamarine is available as a hexagonal crystal that can be up to 29 inches long (1
metre) and flawless. In the 19th century, Aquamarine preferred to be green.Diamond is the
birthstone of April. It is the ultimate gemstone. When they said they were forever, they
weren't joking. The only way to cut or chip a diamond is to hit it with another diamond. These
stones are so clear that loose diamonds can be cut in such a way that they emit a certain
"fire" in their lustre. Due to their properties, they are the most used gem for engagement
rings.Emerald Emerald is the month of birth, the month of rebirth and the celebration of life.
An emerald pendant is traditionally given to mothers on Mother's Day. Emerald is a very
transparent green. Emerald is rarely flawless. The stones are often oiled to fill in the
imperfect emerald cracks. When they oil the emeralds they often help to enhance the colour.
The best emeralds come from Colombia, but there are other good sources like Australia,
India, Austria, Brazil, South Africa, Egypt, USA, Norway, Pakistan and Zimbabwe.Pearl is
the birthstone of June. Well, a pearl is not really a gemstone. A pearl is a solid substance
that is produced in the soft tissues of a living shelled mollusk. Like a mollusk shell, a pearl is
made in the form of minute crystals with calcium carbonate, which is deposited in concentric
layers. The ideal pearl is perfectly round and smooth, but many other shapes of pearl can be
seen.The best quality natural pearls have been highly valued as gemstones and beauty
objects for many centuries, so the term has been used as a metaphor for something very
rare, delicate, admirable and valuable.Ruby is the birthstone of July, and it is so durable and
strong, it is second only to diamond. A perfect gem for everyday wear as a ruby ring or ruby
pendant. An authentic flawless red ruby is more valuable than a diamond. Ruby is one of the
best jewellery settings. It can be red, pink, purple or brown. The colour depends on the iron
content of the stone. If the rubis is fractured, it may be due to continuous twinning. Crystal
prisms are hexagonal and have tapering or flat edges.As Ruby gets bigger they create more
layers.Peridot is the birthstone of August. One of the gem-properties of the mineral olivine is
2. called peridot by jewelers. Peridot has an olive or bottle green colour due to the presence of
iron and a distinct oily or greasy lustre. It has a high bisection. So the doubles of the rear
sides are easily seen in larger specimens. Seen from the front, good quality crystals are very
rare.Sapphire is the birthstone of September. The deep blue colors of twilight are captured in
the intense lively melody of sapphire. Extremely durable and always in fashion, a sapphire
ring in white or yellow gold will never go out of style. All quality corundum that is hot is
sapphire, yet the name is popularly associated with indigo. Due to the impurities of iron and
titanium the colour variation is wide in many shades but the most valuable is a clear deep
blue.Color change Some stones called sapphires display different shades of blue in artificial
and natural light. Good quality sapphires are available in Minmi, Sri Lanka and India.Opal is
used as the birthstone of October. Opal has been a precious gemstone around the world
since its inception or from recorded history. Throughout the ages, culture has revered Opal
as a symbol of hope and purity. The glittering rainbow inside each opal has inspired
imagination from the ancient Romans to Shakespeare's sonnets. Opal is a hard silica gel
that usually contains five to ten percent water. So it is not like other gemstones. It can even
dry out and crack. There are two varieties of precious opal that give a hint of colour
discomfort. Depending on the angle of view of a normal or poached opal, which is often
opaque, the opal shows no opacity.Topaz is the birthstone known for November. Topaz
varies from deep golden yellow in a range of different colors and pink is often the most
valuable of topaz. A blue topaz is almost indistinguishable from aquamarine with the naked
eye. Some topaz has a bubble in the centre. Damage can occur when a gas bubble is in the
topaz as cracks can occur, so choose a good loose topaz before you set it up. The turquoise
birthstone is for those born in December. Turquoise was the first gemstone to be mined.
Because deep blue to green turquoise is very valuable. Turquoise changes color because of
the amount of iron or copper in the rock. Turquoise can cause cracks as it ages. If you wax
turquoise, it can retain its appearance if cracked. Although the best azure blue turquoise is
from Tibet, the Iranian turquoise is more durable.