Guide to Precious Stones

gold cufflinks

Sheila uses both precious and semi-precious stones in her jewellery and ring designs. Apart from cubic zirconia, all our gemstones are natural and are carefully chosen for their quality and colour.

Stones have been set into jewellery since ancient times and are as appealing to us today as they were to our ancestors generations ago.

All Sheila’s gems are set into her jewellery collections and designer rings by hand. Handset stones are often inter-changeable. For example, if you see a ring or piece of jewellery with one type of gemstone in it and you would prefer one of our other gems, or a gem not listed below, it may be possible to do this for you. Please note, however, that setting a specially requested stone into your chosen ring or jewellery makes the piece what we term a “Special”, which means it is non-refundable and non-returnable. If you are interested in a particular stone, do contact us to discuss.

Rings with handset precious and semi-precious stones are a delight to wear as well as to own. We would, however, strongly recommend that such rings are treated as dress rings and are not worn for any manual work, such as cleaning or gardening, which may expose the precious metal and handset stones to risk of damage from heat, chemicals or scratching.

Most gemstones can be safely dipped in silver dip or gold dip but not pearls and great care should be taken when cleaning jewellery set with opals, for further tips see Care of Your Jewellery

The Four Precious Gemstones

2 diamond rings

There are only four stones in the world classified as precious gemstones and we are proud to say we use them all in our jewellery and rings. The “Big Four” are:

Diamond

The hardest naturally occurring material known to man and reputedly a “girl’s best friend”. Diamonds are one of the most treasured stones in the world and feature strongly in our Engagement Rings, Ring Sets and Eternity Rings as well as many jewellery collections. Sheila likes to include diamonds in her gold Diamond Daisies Kiss, Moonlight, Morning Dew, Reef Knot, River Ripples and Rowan in gold. Our Guide to Diamonds has more information about the type of diamonds we use.

Blue Sapphire

After diamonds sapphires are the next hardest gemstone and one of the most valuable. Sapphires belong to the corundum family of rock minerals which also includes rubies. Corundum is a relatively common mineral and its hardness means it is used extensively as abrasives in industry but gem quality transparent corundum is extremely rare. It occurs in many different colours and when red it is known as a ruby. All other colours are known as sapphires with a blue sapphire being the most coveted even though other colours may be rarer. Sapphires are stunning with white gold. Our Celtic Ring can be made in white gold and handset with a blue sapphire.

Red Ruby

A rich red stone from the corundum family which also includes sapphires. Red rubies come from transparent red corundum stone, all other colours of corundum gemstone are known as sapphires. Like sapphires, red rubies are second only to diamonds in their hardness and brilliance, but red rubies are rarer than both diamonds and blue sapphires. Rubies look wonderful handset in yellow and rose gold. Our Celtic Ring is beautiful hand set with a red ruby.

Green Emerald

This richly coloured stone belongs to the beryl group which also includes blue-green aquamarine. Its captivating green colour is unique and unparalleled in all other gemstones. Along with high quality diamonds, blue sapphires and red rubies, the green emerald is one of the “big four” most valued and scarce gemstones in the world. Our Celtic Ring can be set with a green emerald.

High Value Semi-Precious Gemstones

2 diamond rings

Pink Sapphire

Like the blue sapphire, pink sapphires belong to the corundum family. While blue sapphires and red rubies have traditionally been recognised as the most desirable gems, the pink sapphire, which is made of the same type of stone and differs only in colour, is rapidly gaining in popularity and demand. It is sometimes described as a “Pink Ruby” and the classification depends on how the colour is rated. If defined as a red rather than a pink it will be classified as a ruby rather than a pink sapphire. It is certainly a beautiful stone and its lower profile means it is more affordable than red rubies or blue sapphires. Our contemporary diamond ring can be set with a pink sapphire.

Tanzanite

A rare stone with a deep purple sparkle, tanzanite is one of the newest gems available and was discovered as recently as 1967. All tanzanites used in jewellery come from a single mine in the Merarani Hills in Tanzania. This is one area in the whole world where tanzanites occur in abundance. Tanzanite is not quite as hard as the “big four” and only this prevents it being classified as a precious stone, it is as rare if not rarer, highly sought after and beautiful. We are proud to say we use the highest quality triple A tanzanites in our jewellery and rings. If you would like a design featuring a rare tanzanite take a look at Sheila’s beautiful Swirl Ring in white gold.

Opal

A captivating, multi-coloured stone which we use both as a solid white opal and as a black triplet opal. Solid opals are formed from a single opal stone and often feature a wonderful play of colour as the internal structure of the stone diffracts light. Solid opals are very individual stones and can feature pink, red, orange, yellow, green and blue shades through white.

Black triplet opals are not solid opal stones but consist of 3 layers of stone. Our triplets have a layer of dark coloured onyx at the bottom, a middle layer of opal and a top layer of quartz. The dark onyx highlights the play of colour in the opal and the quartz on the top protects the opal. Combinations of green/blue, red/blue or blue/red/green can often be seen.

Take a look at our Moonlight collection in gold if you like solid white opals. Black triplet opals are available on request but are more challenging to match than solid white opals if choosing a set of jewellery or earrings.

Semi-Precious Gemstones

gold ring and broach

Topaz

A very hard gem with excellent clarity offering extremely good value for money. The large 17th century “Braganza Diamond” belonging to the Portuguese royal family, and now lost, is considered to have been a topaz. We use blue topaz of which there are three different types: Sky Topaz is a pale blue stone, Swiss Topaz is a mid bright blue and London Topaz is a darker blue. The bright Swiss Blue Topaz, reminiscent of a blue ocean, is the colour we use in our jewellery. If you like blue topaz you are sure to like Sheila’s iconic Reef Knot collection and Tidal pendant and Tidal earrings in sterling silver with a handset Swiss Blue Topaz.

Peridot

A beautiful green stone belonging to the olivine group of stones, peridots can be mistaken for emeralds. Unlike most other gemstones, Peridot is an “idiochromatic” gem meaning its colour comes from the chemical composition of the mineral itself and not from contact with external materials. As a result, peridots are found in shades of one colour only: green. This gem is becoming ever more popular. It refracts light wonderfully and has a lively, contemporary almost lime green colour which tones beautifully with yellow gold. Sheila has used this entrancing stone in her gold Rowan necklet, gold Rowan pendant and gold Rowan earrings, and in her gold Tidal pendant and Tidal earrings designs.

Garnet

Widely known as a deep red gem, the name “garnet” derives from “gernet” old English for “dark red” and “granum” Latin for “grain or seed”. This may be a reference to the pomegranate whose vivid red seeds can look similar to some garnet crystals. Garnet is also found in other colours but it is the beautiful claret red variety which Sheila has used in Garnet Cathedral in silver.

Rhodalite

Belongs to the garnet group and is also known as Rhodalite Garnet. It tends to be lighter in colour than a garnet, a more pink-red or rose shade, and is often regarded as a higher quality gemstone as it has more sparkle. A rhodalite can be set in the Celtic Ring.

Moonstone

Like opals, moonstones diffract light. Indeed this visual effect gave rise to the stone’s name, its scientific name is sodium potassium aluminium silicate. Moonstone has been used in jewellery and rings since ancient times and is associated with the power and mystery of the moon. We source the top grade of moonstone colour known as fine blue and this is one of Sheila’s favourite stones. Sheila uses moonstone to embellish her designs like droplets of water. It graces her popular Morning Dew, Moonlight, Rowan, Rock Pool, Tidal Islands and Wild Grasses collections in silver. Many of these designs combine a moonstone with a cubic zirconia and some Rowan and Tidal Island designs also include a pearl.

Pearl

Renowned for their lustre, the way the light reacts with the surface, pearls occur naturally in molluscs. We use freshwater pearls from freshwater mussels. If you like pearls, take a look at Sheila’s lovely Lunar Pearl designs in silver and gold, Mill Sands in gold as well as the Rowan and Tidal Islands collections.

Hematite / Haematite

A mineral form of iron oxide, this stone is red when cut or powdered and its name comes from the Greek for “blood”. Unlike other precious and semi-precious stones, hematite is opaque and does not diffract light. Its surface has a magnificent metallic shine and it can look similar to silver when polished. Sheila has used polished hematite stones in several collections notably Mill Sands in silver, Lovers Knot pendant, Lover’s Knot earrings, Dolphin pendant and in some pieces inspired by Orkney’s history such as the Ogham cufflinks, Runic bangle and magnificent Orkney Celtic Connection penannular brooch .

Onyx

This stone is scientifically known as banded chalcedony which is a form of silica containing quartz. Onyz occurs in many colours, notably black, white and red. When red it is known as sardonyx. It becomes wonderfully shiny when polished and is used to great effect in the Orkney Celtic Connection.

Amethyst

The purple variety of crystalline quartz, with colours ranging from pale lilac through to deep reddish purple. Unlike many gems, amethyst is readily available in larger sizes and, due to this, even larger stones are comparatively affordable. Amethyst has been used in jewellery since ancient times and Sheila has set amethysts in jewellery inspired by tradition. Take a look at the Celtic Trinity collection, Celtic Ring and Ogham Kilt Pin.

Citrine

The yellow variety of crystalline quartz from the French for lemon. Citrines vary in colour from yellow to gold through to orange-brown shades. Like Amethysts, Citrines are affordable gemstones and are also available in larger sizes. Citrines look striking set in both silver and gold. Take a look at the Ogham cufflinks and Celtic Ring.

Tourmaline

A gemstone appearing in more colours than any other, tourmaline can exhibit a full spectrum of colours from colourless to black and every tone from pastel shades to dark hues. Often more than one colour is visible in tourmaline. The Celtic Ring looks lovely with a pink tourmaline.

Cubic Zirconia

A bright stone often set in silver as a very affordable alternative to a diamond. This stone is also known by its initials CZ and is the only stone we use which has been produced by man rather than nature. We use European cubic zirconias which are brighter and of a higher quality than normal commercial CZ stones. Like diamonds, CZs come in different colours, and we have lilac, pink and light blue CZs. To see some of Sheila’s designs including white CZs, take a look at her popular Moonlight, Morning Dew, Rowan, Rock Pool, Tidal Islands and Wild Grasses collections in silver. Many of these designs combine a cubic zirconia with a moonstone and some Rowan and Tidal Islands designs also include a pearl. Take a look at Sheila’s Swirl rings (this one and this one) in sterling silver to see both a white and a lilac CZ in the design.

Note: Other stones including birthstones not mentioned above may be available as a special request. Please contact us to discuss on +44 1856 861 203 or info@sheilafleet.com.

Birth Stones

January Garnet
February Amethyst
March Aquamarine
April Diamond
May Emerald
June Pearl / Moonstone
July Ruby
August Peridot
September Sapphire
October Opal / Tourmaline
November Topaz / Citrine
December Tanzanite

There are only four stones in the world classified as precious gemstones and we are proud to say we use them all in our jewellery and rings