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Diamonds, Coloured Stones & Metals


Did you know?

Diamond is the hardest substance known to man that occurs in nature. It is 10 times harder than the second hardest corundum (Sapphire and Ruby). The word diamond originates from the Greek word ‘adamas’ meaning unconquerable. This has given us the word diamond through an old French translation but also ‘adamant’ and curiously enough the word ‘Dame’.

While studying for his honours degree Alan became fascinated by diamonds and assisted by two visits to the DeBeers sorting offices in London completed his final year thesis written on diamonds.

After graduating, Alan was fortunate to be trained in the buying, grading, and sorting of cut gems by reputedly one of the top diamond specialists in Scotland. With his knowledge and understanding of diamonds Alan is widely revered within the diamond industry.

We hear today so much about the 4Cs of diamonds, but do you fully understand what the 4Cs stand for and the impact each has on the look and pricing of the stones.

When buying a diamond or diamonds from Alan P. Fulton, Alan will personally explain to you some of the finer details relating to the 4Cs. This we hope you will find both educational and fun.

Be Aware. DO you know?

That with modern technologies it is possible to manipulate a natural white diamond by enhancing its whiteness and or seemingly to improve its clarity by means of a laser, removing small internal inclusions.

Modern technology has its benefits but unfortunately there are those that want to use it to their unscrupulous ends. Since the origination of these developments there are those who wish to deceive, trading in these far cheaper enhanced stones but selling them to the public as natural untreated, with inaccurate certificates and priced as if untreated.

Detecting stones that have been manipulated can be extremely difficult even for a professionally trained eye using a 10 magnification lens. Identifying a whiteness enhanced stone requires a very well trained eye and a lot of experience. As laser treated, clarity enhanced stones are generally lasered from the underside it is very difficult, even for an experienced eye using a 10 magnification lens, to identify such a stone once set. These stones really need to be assessed loose before being set as some are so cleverly and well done as to be nearly invisible to the trained eye aided by a 10 magnification lens.

White Diamonds can also now be synthesized in laboratories and the industry has again seen these stones sold as natural diamonds with false or fake certificates at grossly inflated prices.

Although these manipulated and manufactured diamonds have their place buyers should be very wary.

Alan advises that when purchasing diamonds they should be purchased from a reputable source, preferably a source with a shop front presence or if buying on line a source with clear contact details, phone number, and an office or premises address that can be checked out.

Colour. Did you know?

The scale used for grading the colour of diamonds is an alphabetical scale starting with the top colour of ‘D’ and working down from there. This scale is not a uniform sliding scale so the difference in colour between a ‘D’ and an ‘E’ is less than that of an ‘E’ to and ‘F’. In fact, the difference in colour between a ‘D’ and an ‘F’ is nearly the same as that between a ‘G’ and an ‘H’.

As there is a very small difference between the colour grades it is difficult to determine a colour accurately without using a comparison. This is something Alan will do with you.

Clarity. Did you know?

A good percentage of small black marks that occur in diamonds are not, as commonly believed, carbon marks but actually small crystals of the semi-precious stone garnet.

The clarity of a diamond is determined by the size, the number, and the position of the mark or marks within the stone. These marks are determined by use of a 10x loop or a lens with a 10x magnification. When purchasing diamonds from Alan P Fulton Alan will give you a lens to let you see the clarity for yourself.

With Alan’s knowledge, experience, and expertise, you will be left in no doubt that the diamond or diamonds you purchase are the correct stones for you and will be mounted in a way to suit your requirements and maximise their brilliance.

Cut. Did you know?

The Indian name for diamonds is ‘Vajra’, the same word they use for a thunderbolt or lightning.

The cut of a diamond not only relates to the shape of the stone but also the uniformity and number of the facets. A correctly proportioned modern round brilliant cut will reflect 100% of the light that goes into the stone back out. Not many of the other cuts, if any, do this!

Carat Weight. Did you know?

The first people to know and use diamonds were the Dravidians who lived in India around 700 – 800 B.C. It is from these people that we get the unit of weight ‘the CARAT’ as apparently they thought diamonds grew in the ground like turnips and weighed them on their balance scales against the seeds of the carob tree which they called ‘cattie’ or ‘carat’.

The size of a diamond is regulated, not so much by its dimensions in millimetres, but by its weight. The carat weight of a diamond is the unit used and this unit of 1 carat is broken into 100 smaller units called points, hence 100 points makes 1 carat. As a unit of weight you will comprehend, 1 carat is equal to 0.2 grams.

Coloured Diamonds

Diamonds occur in nature naturally in a variety of colours white, steel grey, blue, green, yellow, orange, red, pink to purple, brown, and black. The colour of a diamond may be affected by chemical impurities in the crystal lattice. Depending on the hue and intensity of a diamond’s colouration, a diamonds colour can either enhance or detract from its value. The price of most white diamonds is affected by the amount or subtlety of yellow or brown hue detectable through the stone, with the price discount increasing in relation to the amount of this discolouration. Only when the colouration is intense enough and uniform throughout the diamond does the stone merit being classed as a ‘coloured fancy’, such as a Canary Yellow. Due to their rarity these natural occurring ‘coloured fancies’ can be, and generally are, many times the price of natural white diamonds.

With modern technologies, it is now possible to change the colour of a natural white diamond through a process called HTHP ( high temperature, high pressure ). This process imitates or mimics nature’s way of colouring diamonds that took place deep in the Earth’s mantle at around 87 – 118 miles ( 140 – 190 kilometres ), between 1 and 3.3 billion years ago. Natural polished white diamonds are re-exposed to the environmental conditions they require in order to bring out their hidden colours.

This development, Alan believes, opens up possibilities for everyone to own a ‘coloured fancy’ diamond, something that was only attainable by the rich and famous. Be wary though, these diamonds should be sold as ‘treated’ and generally at prices that reflects this – so it is vital that if considering purchasing a coloured diamond you should consult a trusted and knowledgeable dealer.

The pricing of the treated coloured diamonds varies and is dependent on the colour. Due to their rarity treated pink and deep reds tend to be the most expensive and can be up to a few times the price of their equivalent in a natural white diamond. Ocean blue, Champagne and Cognac colours are amongst some of the less expensive with some only 10 – 15% more expensive than their equivalent in a natural white diamond.

Below is a list of recognised colours that can be sourced, however, it should be noted that stones should be viewed before purchasing as the diamonds do come in many subtle hues between the colours listed.

List of coloured diamonds available

Ice Blue, Sky Blue, Ocean Blue

Forrest Green, Olive Green, Apple Green, Pine

Sunny Yellow, Canary Yellow, Gold

Cognac, Orange Cognac, Red Cherry


Coloured Stones

Sapphire is a precious gemstone of the mineral corundum, an aluminium oxide. Although typically associated with the colour blue, natural ‘fancy’ sapphires also occur in purple, pink, yellow, orange, and green colours. Some ‘party sapphires’, also known as colour change sapphires, show two or more colours. The only colour which sapphire cannot be is red – as red coloured corundum is called ruby, another corundum variety.

Trace amounts of elements such as iron, titanium, chromium, copper, or magnesium present during the formation of corundum crystals are responsible for the colours of a sapphire. Titanium and Iron impurities produce a blue colour while chromium impurities in corundum produce a pink hue.

The quality of a sapphire is determined by its colour, cut, and clarity. All of these properties, together with carat weight, affect the value of a sapphire.

A star sapphire is a type of sapphire that displays a star-like phenomenon known as asterism; red stones are known as ‘star rubies’. Star sapphires and star rubies contain a particular type of inclusion that interferes with the crystal structure causing the appearance of a six-rayed ‘star’-shaped pattern when viewed with a single overhead light source. These stones are not faceted but cabochon cut.

Due to corundum’s remarkable hardness – being the third hardest natural occurring mineral after diamond and moissanite – sapphires and rubies are ideal stones for inclusion in engagement rings and dress rings alike.

Sapphire is the birthstone for September, the stone for the Zodiac sign Taurus and the gem of the 45th wedding anniversaries.


Ruby is a pink to blood-red coloured precious gemstone of the mineral corundum, an aluminium oxide. The red colour is caused mainly by the presence of the element chromium. Its name comes from ruber, Latin for red. Ruby is considered one of the four precious stones, along with sapphire, emerald and diamond.

The quality of a ruby is determined by its colour, clarity and cut. All of these properties, together with carat weight, affect the value of a ruby. The brightest and most valuable ‘red’ called blood-red or ‘pigeon blood’, commands a large premium over other rubies of similar quality. After colour comes clarity – similar to diamonds, a clear stone will command a higher price. Cut and carat (weight) are also an important factor in determining the price.

Ruby is traditionally the birthstone for July, the stone for the Zodiac sign Aries and the gem of the 40th wedding anniversary.


Emerald is a green stone of the mineral beryl. Another well-known gem stone of the beryl family is Aquamarine.

The word ’emerald’ comes through Old French and Middle English translations of Latin which originated in Ancient Greek ( smaragdos; ‘green gem’ ).

Emeralds, like all coloured gemstones are graded using four basic parameters – the four Cs, Colour, Clarity, Cut and Carat weight. Normally, in the grading of coloured gemstones, colour is by far the most important criterion. However, in the grading of emeralds, clarity is considered a close second. A fine emerald must possess not only a pure verdant green hue as but also a high degree of transparency to be considered a top gem.

In the 1960s, the American jewelry industry changed the definition of ’emerald’ to include the green vanadium-bearing beryl as emerald. As a result, vanadium emeralds purchased as emeralds in the United States are not recognized as such in the UK and Europe. In America, the distinction between traditional emeralds and the new vanadium kind is often reflected in the use of terms such as ‘Columbian Emerald’.

Emerald tends to have numerous inclusions and surface breaking fissures. Unlike diamond, where the ‘loupe’ standard, i.e. 10 – magnification, is used to grade clarity, emerald is graded by eye. Thus, if an emerald has no visible inclusions to the eye (assuming normal visual acuity) it is considered flawless. Stones that lack surface breaking fissures are extremely rare and therefore almost all emeralds are treated (‘oiled’) to enhance the apparent clarity. The inclusions and fissures within an emerald are sometime described as ‘Jardin’ (French for ‘garden’), because of their mossy appearance.

Although Emeralds are relatively hard they tend to be brittle due to the fissures within the stones which leads to the faceted emeralds being most commonly cut as Ovals, or the signature Emerald cut, a rectangular cut with a flat facet instead of a sharp corner.

Emerald is traditionally the birth stone for May, the stone for the zodiac sign Pisces and the gem of the 55th wedding anniversary.


There are many, many, Semi-Precious stones with many varying visual qualities and colours, too many to go into in any depth within this page on our website.

Some stones that we generally hold in stock or regularly asked to source are – Tansanite, Aquamarine, Tourmaline, Topaz, natural occurring Blue Zircon and Amethyst.

Pearls, whether freshwater, or south-sea with their many varying colours and hues can be sourced as individuals or in strings.

Coral, although endangered in many parts of the world where farming is banned, there is one source that for a short period each year farming of a controlled quantity is allowed. We can source this coral which is generally of a top quality and colour, as individual pieces or in strings.



While studying for his honours degree Alan studied metallurgy, and in particular the structures and properties of silver, gold, and platinum. Having the knowledge and understanding of this information is important when hand working the materials so that you can maximise the benefits of their durability, ductility, malleability, and reflect ability.

Hardness & Durability

The hardness, or more importantly the durability of a metal or alloy is dependent on a number of factors, three of which are explained as simply as possible below.

The durability ( resilience or toughness to wear ) of any jewellery item, but in particular rings, can be attributed to three main factors. 

  1. The hardness and durability of the basic metal.
  2. The metal or metals added to create an alloy.
  3. Whether the jewellery is made from a wrought metal alloy or cast.

Each of the four precious metals we use, Platinum, Palladium, Gold, and Silver, has different properties of hardness and durability in their purest form. Generally they are all alloyed with other metals to harden or give different working properties and with gold, in particular, the addition of some metals to bleach it white.

Factor 3 has been highlighted, as with any of the metals, a cast item is generally softer and more brittle than an item created from wrought or forged metal. This is due to the addition of metals in the alloys to allow the metals to flow while molten but mainly due to the fact the metal of the item created by casting is less dense, being infested throughout with microscopic, and on occasions larger, air bubbles known as porosity.

From his vast experience over the years of working with the metals and carrying out his own experiments, comparing forged and wrought metal items with cast items, Alan has found the forged and wrought metal items to be more durable than cast with some forged platinum rings quite markedly three to four times more durable.

Alan has also produced his own sliding scale for the durability ( resilience or toughness to wear ) of the wrought precious metal alloys most commonly used. The scale listed below is solely Alan’s, assessed from his vast experience and many years of working with the metals. The scale assumes the Platinum 950 grade of alloy having a level of 10.


Wrought Alloy                                 Hallmarking Grade                                        Alan’s Durability Rating  


Platinum                                                         950                                                                           10

Palladium                                                       950                                                                            6

White Gold                                                     750  ( 18ct )                                                            5.5

Yellow / Red Gold                                        375  ( 9ct )                                                               5

Yellow / Red Gold                                        750  ( 18ct )                                                            4.5

White Gold                                                    375  ( 9ct )                                                               4.5

Silver                                                               925 ( sterling )                                                        4



Did you know ?

It is estimated that all of the platinum ever mined would fit in the average size living room.

It was the South American Indians of Columbia who were the first known peoples to use platinum some time before 1735. It was in this year that the Spaniard Antonio de Ulloa discovered the Indians using the metal and sent it back to Europe. The name Platinum comes from the Spanish platina – little silver.

Platinum is the rarest and heaviest of the precious metals. Platinum is recovered from a black ore that looks for all the world like coal. Ten tons of this ore and a five months process are required to produce 1 ounce of Platinum bullion. Approximately 133 tons of platinum are mined every year around the world. It has a melting point of 1772 C., which is far higher than gold or silver, and is alloyed with most commonly copper, to produce the hallmarking standard of 950 – which means 950 parts per 1000 are Platinum. The remaining 50 parts is normally copper to allow the Platinum certain working and wearing properties, but also ruthenium and iridium are used.

Platinum is one of the most ductile metals known. Ductile meaning the ability to be drawn down into finer and finer wire. Platinum can be drawn down to a wire that is half the thickness of a human hair. It is also a very dense metal – or if you like a heavy metal. In comparative terms it weighs approximately 1.35 times the weight of 18ct.gold and nearly twice the weight of sterling silver.

Platinum is by far the hardest and most durable of the precious metals we use so is ideal for use in stone settings and shanks of engagement rings and wedding bands. As with all precious metals, Platinum can be scratched, however, with Platinum, there is actually no material lost from the scratching as there is with gold. This is due to the molecular structure of platinum being ‘sticky’- the molecules want to stick together like blue-tack. This is not the case with gold or silver.


Did you know ?

Palladium was discovered by Norfolk chemist and physician William Hyde Wollaston in 1803. He named the metal Palladium in 1804 after the asteroid Pallas, discovered two years earlier, and the Greek goddess of wisdom.

Approximately 24 tons of palladium are produced around the world annually. It has a melting point of 1552 C. which is a good bit higher than silver and gold but not as high as platinum.

Palladium has for some time been alloyed with gold to bleach it white and produce white gold, commonly used in the production of jewellery.

Until recently, and apart from a short period during World War 2 when platinum was declared a strategic government resource and palladium was used for jewellery bands, palladium’s use in jewellery has been confined to its use in producing white gold. In 2006 however some bullion dealers started producing palladium in forms suitable for jewellers. Since then it has made a meteoric rise in popularity amongst jewellery designers and watchmakers and is seen as a very good substitute for white gold.

Palladium has joined Gold, Silver and Platinum as the fourth recognised precious metal. This means articles cannot be sold in the UK without a statutory hallmark.

We are led to believe by the bullion companies that in 2006 Alan was the first jewellers in Scotland to hand make in palladium. The standard of alloy we use is 950, 950 parts per 1000 palladium, the same standard as is the hallmarking standard of platinum.


Did you know ?

Pure gold is one of the most malleable metals known – 1cm3 – barely the size of a sugar cube can be beaten or rolled into thinner and thinner sheet that would spread more than 1 meter square. The sheet can be so thin as to be translucent.

Gold is 1 of only 2 metals occurring in nature that are coloured, the other being copper.

Every year approximately 1,700 tons of gold are mined around the world mainly in South Africa, USA, Canada, and Russia. It is estimated that 147.3million ounces of gold, which is estimated to be 2.3% of the gold ever mined since Egyptian times, is stored in the United States Treasury Department’s gold depository at Fort Knox Kentucky, considered to be the most secure building in the world.

Pure gold has a melting point of 1064 C and is very soft so other metals are added to it in varying quantities to make it harder and also alter its colour. The term used to describe the fineness of these alloys is CARATS. The hallmarking standards in Britain are –  9ct. 14ct. 18ct. 22ct.

9ct. – 9 parts per 24 gold or 375 parts per 1000
14ct – 14 parts per 24 gold or 585 parts per 1000
18ct – 18 parts per 24 gold or 750 parts per 1000
22ct – 22 parts per 24 gold or 916 parts per 1000

The metals that are added to make these changes are;

SILVER  acts to harden gold in conjunction with copper. Silver also whitens its colour.

COPPER  reddens gold and hardens it especially when added with silver.

ZINC  Significantly lowers the melting point of gold alloys so is perfect to add when making solders. Zinc also acts as a secondary whitener.

PALLADIUM  is a primary whitener of gold especially in 18ct. alloys. It also hardens gold and raises the melting point considerably. 1180 – 1235 C


Did you know ?

Silver is one of the most reflective metals known. It reflects colours more accurately than any other metal. It has an optical reflective ratio of 97%.

Because of its reflective properties and before the advent of digital technology, silver was exclusively used in photography, both on the film in your cameras and the papers used to print your enlargements. In the past the reflector plate of a good quality mirror was also made from silver.

Silver is also a very malleable material and this combined with its reflective properties makes it the perfect material from which to make large decorative objects such as tea and coffee pots, candelabras, and table centres.

Approximately 9950 tons of silver are mined each year around the world. Silver has a melting point of – 961 C – and is the softest of the four noble metals. It is therefore alloyed with copper to make it harder. The British minimum standard for a silver alloy is commonly known as ‘Sterling Silver’ or depicted by the numbers 925. This means there are 925 parts per 1000 silver and 75 parts copper.

Although silver requires the copper to harden it, the inclusion of the copper has been and is the scourge of many a silversmith over the centuries. The reason for this is that under heat, annealing and soldering, the copper through the alloy and just under the surface oxidizes. If this is left on the metal when polished it shows as a greyish-brownish stain. This is called fire stain. To get a good polish on any silver item all of this staining requires to be removed which causes in some cases a fair amount of work.

Many mass produced jewellery items are plated with a thin layer of fine silver or other whiter metal such as rhodium to mask this discolouration. This plating wears off over time revealing the fire stained silver beneath.