30/04/2016
The Modern Birthstone chart is the official birthstone list from the American National Association of Jewelers. January – Garnet February – Amethyst March – Aquamarine April – Diamond May – Emerald June – Alexandrite July – Ruby August – Peridot September – Sapphire October – Opal November - Topaz or Citrine December - Turquoise Tanzanite, or Blue Zircon
Cabochon is a stone that is cut with a highly polished rounded or convex top with no faceting, with a flat or slightly domed base. A cabochon may be cut in any shape, though oval is by far the most common. The term comes from the French caboche, meaning k**b or small dome.
Gold is a highly sought after precious metal which has been used since prehistoric times for making jewelry, coins and ornaments. The purity of gold is measured in karats pure gold 24K is very, very soft - One gram nugget of pure gold can be hammered into a sheet one meter square. Due to the softness of the metal. When it's used for jewellery production it has to be alloyed with other metals. This therefore the hardness durability colour and various other properties of the gold is altered. For example, to create Rose Gold, 25% copper is added to the melt with 18k gold. South Africa leads the way in gold extraction in the 1800's the country produced around 50% of the world's total output. In the late 1900's it was up to 79%. This number has since declined, mainly due to the difficulties extracting the metal. Since 2007 China leads the way in gold output. Gold plating is a process that applies a layer of gold to a surface of another metal usually silver or copper to give it a brighter lasting finish. Gold Filled jewellery can also be referred to as rolled gold this technique comprises of a solid gold layer bonded with heat and pressure on to a base metal such as brass. This can give the base metal the look and luster of 14K quality gold.
Mohs Scale In the case of minerals and gemstones, hardness refers first to scratch hardness then to cutting resistance of each mineral. Friedrich Mohs introduced the term scratch hardness. The following table shows the scale that he developed which is still in use today. Diamond 10 / Ruby & Sapphire 9 / Beryl 8.5 / Topaz 8 / Aquamarine & Emerald 7-8 Zircon 7.5 / Tourmaline 7-7.5 /Garnet 6.5-7.5 / Amethyst, Chalcedony & Quartz, 7 /Jade & Peridot 6.5 / Moonstone 6-6.5 / Opal 5.5-6.5 / Turquoise 5-6 / Lapis lazuli 5-5.5 / Glass 5 Azurite 3.5-4 / Bronze, Coral & Pearl 3 / Gold 2-3 / Amber, Ivory, Shell & Jet 2.5
Platinum is a white coloured precious metal that is very strong and dense. Jewellery made from Platinum is usually 90-95% pure metal. Platinum is 60% heavier than gold it wasn't discovered until the 1700's in Russia. To increase the strength and workability of the metal it is alloyed with Ruthenium, Palladium, Iridium and Osmium which are all members of the Platinum family.
Silver gets its symbol (Ag) from the Greek word Argyros. Silver is a fine, precious metal. Its colour is silver-white and it is often used in jewelry. Silver has to be alloyed (mixed) with other metals in order to use in jewellery production. This mixing of metals makes it more durable and rigid. Jewellery and Silverware are traditionally made from sterling silver an alloy of 92.5% silver with 7.5% copper. Silver is often plated with rhodiumfor a bright shiny look which does not tarnish as quickly. However, under normal conditions with no plating, Silver will tarnish - it's the mixture of moisture and sulphur in the air we breathe that causes this. The main area of the world that silver is mined today is Russia. The country produces around 15% of the world's total output, closely followed by Mexico. Canada, the USA, Peru, Bolivia and Germany.
Vermeil is a French word that was introduced in to the English language in the 19th Century. Vermeil is a process where sterling silver is plated with Gold at least 10K and the layer has to be 1.5 micrometers thick to be considered true Vermeil.
White Gold is a gold alloy that is mixed with at least one white metal usually nickel or palladium. Like any other gold its purity is measured in karats. Almost all white gold jewelry is rhodium plated since gold alloyed with Palladium or nickel never comes out white but tinted brown. It is therefore plated with rhodium to mask the tinted shade and make it a true white colour.
Abalone is a type of Mother of Pearl and is also known as the paua shell. For centuries the Maori tribes of New Zealand have used Abalone for mystical carvings and jewellery. This mollusks shell has been referred to as sea opal because of its colourful resemblance to the opal.
No stone is more creatively striped by nature than Agate. It's found in a wide range of colours including black, grey, brown, yellow, pink and blue. Agate is a porous stone and can be dyed to enhance the colour. In ancient times the stone is said to have had the power to quench the thirst and protect against fever. The mining of agate was documented as early as the 1490's in Germany.
Alexandrite is a mineral that changes colour dependant on whether it is viewed in natural or artificial light. Alexandrite can appear red in candle light and blue/green when in fluorescent light. The stone was first discovered in 1834.
Amber is an ancient and valuable stone which is sourced from fossilized tree resin. It is also a natural hydrocarbon that comes in many colours ranging from yellow to brown to blue. In the past it was thought that Amber possessed magical powers and protected the wearer from evil. Due to the nature of the source amber can sometimes contain small insects. The two main sources of Amber today are The Baltic's and Dominican republic.
Amethyst is the most striking member of the crystal quartz family. It's usually purple in colour, however crystals have been know to have a colour range of milky white to a very pale lavender. The ancient Greeks believed it to have the power to make the wearer immune to the affects of alcohol. Large deposits of the stone have been found in Brazil and neighbouring Uruguay. Another major source is Madagascar.
Aquamarine got its name from its seawater-like colour which, in Latin, translates to Water of the Sea. Aquamarine is a cousin of the Emerald, as they both belong to the Beryl family of stones. This beautiful stone can be found in many countries: Australia, Burma, China, and Zimbabwe to name a few.
Azurite is a copper based mineral that is often used in jewellery. Its colour ranges from very dark green to very light blue. There are many sources of the stone and it can be found in the USA, Southwest Australia, Zambia, Morocco and Mexico.
Coral is an organic gemstone. The distinguishing features of precious coral are its durability and intensely coloured skeleton. The coral typically grows on rocky sea beds at depths of between10-300m in areas around Japan, Taiwan and near the straights of Gibralter.
Crystal is high quality glass containing at least 10% lead oxide. Lead is added to the melting process to produce a very clear glass that resembles rock crystal. The process of making lead crystal was discovered by the English glassmaker George Ravenscroft in 1676. Crystal is coloured by adding various metal oxides during the melting process.
Cultured Pearl long ago pearls were seen as a financial investment alongside property and artwork. They were so rare because they were created by chance in the sea. Today, however, Pearls are created artificially by placing shell beads into the oyster which is then placed back in the sea for several years. Most of the cultured pearls today are created in Japan in the warm waters of the South Pacific. Tahitian Black Pearls are created from larger oysters and freshwater pearls are created inside mussels from China. This method of creating pearls was invented in 1893 by Kokichi Mikimoto.
Cubic Zirconia a very inexpensive stone that is created in laboratories and used as a cheaper alternative to diamonds. They were first developed back in 1977. When created, the stone is usually optically flawless with no colours. However, colours can be added during the forming process with chemicals.
Diamonds get their name from the Greek word adamas which translates to The Unconquerable. Diamonds are very precious and optically very beautiful. Due to its visual beauty and hardness the diamond is regarded as the king of gemstones. Diamonds are formed from carbon (basically coal) that crystallises under immense pressure over a very long period of time. Until the 1800's diamonds were only found washed out of volcanic pipes that release the diamond bearing rock out into the earth's natural environment. The most famous pipe in South Africa is the kimberly mine where mining was discontinued in 1914. Today, Australia leads the way in Diamond production closely followed by China and Russia. A Diamond's value is decided by the four C's Carat, Clarity, Colour and Cut. Diamonds are found in many colours - mostly a yellowish colour until given various treatments. The rare colours are green, red, blue and purple. These stones are very valuable and have been known to fetch collector's prices.
The name Emerald derives from the Greek word Smaragdos which literally means green Stone. Emerald is the most precious stone in the Beryl family which includes aquamarine, golden beryl andmorganite. The finest specimens of emerald are clouded by occlusions. These are not necessarily faults in the stone as they can be used to prove that the stone is genuine. These occlusions are referred to by experts as jardin. Significant deposits of Emerald are found in Columbia, however only a third of the stones from the Columbian deposits are worth cutting. Good quality specimens have been mined in Zimbabwe where the crystals are small but of a gemstone standard. Other known deposits of Emeralds can be found in Brazil, Afghanistan, India, Ghana and Zambia to name a few.
A vitreous Enamel surface is achieved by fusing glass particles to sheet metal or cast iron and firing it at temperatures in excess of 800°C. This results in a surface that is incredibly hard-wearing to all the elements. It is temperature resistant (up to 800°C) and chemical resistant with exceptional colour stability. The finished enamelled product is easy to maintain, and to keep clean. Natural Enamel is very expensive which is why most of today's Enamel is synthetic.
If you thought Garnets were only red, A Garnet is a group of stones which includes around 20 different variations, such as; andradite, hessonite and rhodalite to name a few. Garnets have a wide range of colours and the only colour that they don't appear in is Blue. A
Howlite also referred to as snow white is a very soft mineral which is white to grey in colour and occasionally has black veins running through it. Howlite is usually dyed to create imitation turquoise. Howlite gets its name from the geologist who discovered it, Henry How.
Jade is a semi-precious stone that has a wide range of colours from green to black to white to brown. Translucent jade is more sought after and valuable than opaque jade. For thousands of years the Chinese have regarded Jade to possess medicinal properties. There are two different minerals that are known as jade jadeite and nephrite. Jadeite is the harder of the two mineralsand is more often used in jewellery. It can be mined in China, Russia and Guatemala.
Nephrite is slightly softer and is often used for carving bowls and vases nephrite has been sourced in China, New Zealand, Russia, Guatemala and the Swiss Alps. There is also the Dark green Jade known as Canada Jade, which is found in Western Canada.
Jasper is derived from the Greek meaning the spotted one. Jasper is a very common stone which is opaque in appearance. It has many colours and patterns. Sometimes it has been known to have a panoramic pattern similar to that of a landscape. There are many varieties of jasper agate-jasper which is yellow to brown in colour. Egyptian jasper is also known as a nile pebble which has a strong yellow and red colour. Basanite which has a fine grain is black in colour. The stone has been discovered all over the world including Egypt, Brazil, India and Canada.
Jet is also known as gagate. Jet is fossilised coal which is hard and very lightweight. Genuine jet is warm to the touch and can be distinguished from synthetic jet which is usually made from black glass or plastic. Jet has been mined in Whitby in UK as far back as prehistoric times. It has also been mined in Russia, Germany, France and Spain; however these sources are said to be inferior to the one in the UK.
Lapis Lazuri is a very rich blue colour. This semi precious stone is made from rock, not mineral. The stone is porous and quite soft and scratches very easily. Because of this if Lapis is left in water too long it will dull the sheen. Lapis is regarded by many people around the world as the stone of friendship. It has been mined in Afghanistan for over 6,000 years. Chile is said to have extracted lapis of a quality that can compete to that of Afghanistan.
Malachite is an opaque semi-precious stone with very deep and light green layers, sometimes with thick veins of black running right through it. Malachite is often coated in a colourless wax, oil or hardening agent to enhance appearance and increase durability. The main source for malachite is the copper mines of the Democratic Republic of Congo, Zambia, Mexico, New South Wales, Israel and Australia. In Israel, Malachite is mined in the Timna Valley which is also known as King Solomon's mines.
Marcasite or fool's gold is a mineral that is sometimes referred to as white iron pyrite. It can often be mistaken for pyrite but marcasite is lighter in colour and more brittle. One famous source of marcasite is Dover in the UK.
Moonstone is a semi-translucent stone which can appear in several colours. It is usually whitish- blue however it can be found in grey, orange or red and sometimes even appear with no colour at all. Deposits of Moonstone can be found in the following countries; Mexico, Tanzania, Myanmar, Madagascar and Sri Lanka. It can also be found in the USA, specifically Pennsylvania and Virginia.
Mother of Pearl is an organic material produced by some mollusks on the inner layer of their shells. This material is very strong, resilient and iridescent. It has many uses from jewelry to pistol handles. The main sources of Mother of Pearl are the warmer waters of Asia. The freshwater water variety can be found in many rivers across the USA, Europe and Asia.
Onyx comes from the same Greek word which translates to nail or claw. Onyx is a member of the chalcedony quartz family. Its colour is usually black or white. This stone was very popular with the ancient Greeks and Romans.
The word Opal derives from the Sanskrit word ôupalaö which means valuable Ssone'. Opals are divided into 3 subgroups: Precious Opals, Fire Opals and Common Opals. Their physical properties vary considerably. Precious Opal's special characteristics are its play of colour. It displays rainbow-like colours that can be seen right through the stone - especially in round cut stones. Types of precious opals are white, black, matrix, boulder, harlequin jelly and crystal. Fire Opal named after its orange colour is usually milky in appearance. However, its best qualities can be clear and transparent which are suitable for faceting. Common Opal is opaque and rarely translucent It shows no play in the colour and has a wide range of trade names agate angel, skin, wood, honey, hyalite, hydrophane, porcelain, moss, girasol, prase, and wax. In order to display the stone's best qualities it must be polished and cut in to round or oval cabochans. Opal has a high water content sometimes as high as 10% if the stone becomes dry it can become brittle and cracks may start to appear. The colour will also appear to fade. For this reason, Opal must be worn by the owner as often as possible so the stone will receive the required amount of air and humidity. The best way to store Opal is to place it in damp cotton wool. Almost 95% of the world's Precious Opal originates from Australia. Deposits of Fire Opal can be found in Brazil, Mexico, Guatemala and the USA.
Peridot can also be referred to as olivine it has a vivid green colour which is a perfect colour to be worn in the summer months. This stone can be found in abundant quantities in Pakistan and Afghanistan.
A porous material is a solid object filled with pores or gaps these gaps can become filled with either a liquid or a gas. There are many examples of porous materials in the world today; bones, cement and foam to name just a few. Porous Gemstones can be injected with colour to give them a more vibrant colourful finish.
Rhinestones are highly reflective glass pieces cut and polished to imitate gemstones. The original rhinestones were quartz stones. The best made rhinestones today are formed from highly reflective leaded glass which is cut and polished. Rhinestones were initially sourced from the rhine river.
Rhodium is a white precious metal that is quite expensive and often used in the plating of base & precious metals to give it a platinum-like sheen. The main source of this alloy is South Africa.
Rhodolite which means rose stone in Greek is a member of the garnet family. It has a colour range from purple-red to pink-red. The main deposits of the stone are Sri Lanka, Zimbabwe, Kenya and the USA.
Rock Crystal is one of the most common minerals of the earth's crust. The name crystal comes from the Greek for ice. It was believed that rock crystal was eternally frozen. Important deposits have been found in Brazil, Madagascar, the USA, and the Alps. They are often used for costume jewellery and delicate ornaments to imitate diamonds. It can be confused with many colourless gems as well as glass.
Rose Quartz is named after its pink colour. It's a form of quartz that can have traces of rutile needles which can cause a six-rayed star when cut into cabuchon. Deposits are found in Brazil and Madagascar as well as India, Namibia and Sri Lanka.
Rubies are a very precious member of the corundum family. The colour range is a deep red to purple/brown. The most sought after colour of the stone is what has been referred to as pigeons blood its a pure red colour with a hint of blue. As a rough stone ruby appears dull and greasy however when cut and polished the lustre can come close to that of a diamond. Just like emeralds occlusions in the stone can identify its authenticity. During the renaissance period rubies were thought to have the power to counteract poison. Some of the most important deposits are in Burma, Thailand and Tanzania with only one percent of the rubies mined in these areas are of a gemstone quality.
Rutilated Quartz is a type of rock crystal which contains long, fine needles of rutile crystals (titanium dioxide). This beautiful stone is usually cut as a cabochon. It is also known as cupid's darts, and fleches d'amour (arrows of love).
Sapphires are a very precious stone that has a wide range of colours from blue to white, green to purple. Sapphires are part of the corundum family and in ancient times sapphires were worn to protect the wearer from poisonous creatures. The finest specimens of sapphires are now mined in Kashmir but have also been mined in Thailand, Australia and China.
Smokey Quartz is brown in colour and has a smokey appearance. Smokey Quartz can sometimes have rutile needle occlusions. Deposits have been found Brazil, Madagascar, Russia, Scotland, Switzerland and the Ukraine.
Sunstone is also called Aventurine this gemstone varies in colour from golden to orange from red to brown and can sometimes contain a green or blue glitter effect caused by light reflections. The stone is usually cut flat or into a Cabochan. It can be found in several countries including India, the USA, Norway and Canada.
Tanzanite is a variety of the mineral zoisite. Tanzanite in its roughest form is a reddish almost brown colour. It has to be treated at a very high temperature to produce that unique blue/purple colour it is famous for. The correct name for Tanzanite is Blue Zoisite. Tiffany's The jewellers however thought this name wasn't appropriate so it was named after the country where it was discovered in 1967, Tanzania. Tanzanite is a rare gem found mainly in the foot hills of Kilimanjaro.
Tiger's Eye is member of the quartz group. This semi-precious stone is dark brown to yellow in colour with red colour being produced by applying heat to the stone. Tiger's Eye that is honey in colour is sometime passed off as the more expensive cat's eye'. Blue to grey coloured versions of the stone are called hawks eye and the dark brown version of the stone is known as bull's eye or Ox-eye. For jewellery the stone is mostly cut into cabochans to bring out the streaks of colour that run right through the stone. The biggest percentage of Tiger's Eye comes from South Africa where the export of raw materials is forbidden. Other sources have been Brazil, Burma, Canada, China and India.
Topaz in its purest form has no colour. It is usually coloured by the impurities from the surrounding land. Topaz can be found in many colours, some of which do not occur naturally. Mystic Topaz for example is created by applying an artificial coat to the stone which gives it that magical look. Blue Topaz in its natural form is very rare so manufactures heat treat colourless topaz to create a deeper blue more vibrant than a natural stone will ever posses. Topaz can be found in many countries including Germany, Japan, Norway, the USA, Sri Lanka, Afghanistan and the Czech Republic.
Tourmaline is a gemstone with the widest colour range of any gemstone the lighter colours being the most valuable. There are many variants of this stone which make it easier to break down the colour range. Rubelite can be rose red to pink in colour, Shorl is black in colour, Indicolite is light blue to a pale green, Verdelite is green and Achroite is colourless. Gemstone quality Tourmaline is mainly mined in Brazil and Africa, but have been sourced in Kenya, Nigeria, Namibia, Madagascar, Mozambique, Pakistan, Afghanistan, Sri Lanka, and Tanzania.
The name Turquoise means 'Turkish Stone it gets this name from the route it took to get into Europe. Turquoise is a porous semi precious stone. It can have either a blue or green coloured surface with veins of black running right through it. Turquoise can be very soft and may be treated with a wax to help preserve the stone's life a little longer. The finest specimens of the stone come from deposits in Persia, Iran. Other well known deposits are in the USA, Israel, Afghanistan, Mexico and China.
Zircon is a mineral that can appear in many colours from colourless to red to brown to green. Colourless specimens that show gem quality are a popular substitute for diamonds. Zircon is not to be confused with cubic zirconia, which is a synthetic substance with a completely different chemical composition. Zircon is a very common mineral that occurs worldwide from Australia to Quebec. Australia leads the way in mining this mineral producing 37% of the worlds total output.
Zoisite has three known forms Anyolite, Tanzanite and Thulite. They are green, blue and pink in colour respectively. Zoisite was named after Slovenian mineral collector Baron Sigismund Zois von Edelstein who financed the expedition that discovered Zoisite. Zoisite can be sourced in Tanzania (Tanzanite), Kenya (Anyolite), Norway (Thulite).
