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Jewellery Guides

A Guide to Gemstones

Gemstones from A to K

Discover the range of gemstones Cassandra uses in her jewellery designs. From recognisable to rare and obscure gemstones, delve into the world of gemmology and explore new and unusual gemstones and the jewellery created with them.  


The curved banding of agate makes the body colour of this quartz the most interesting ornamental gemstone. Large slices of agate can make unusual pendants showing
off their unusual crystal structure.



Like the deep waters of the Amazon river, Amazonite holds captivating shades of turquoise green. A feldspar mineral that forms in tabular crystal structures, usually cut as cabochon due to its fragile nature. It has a vitreous lustre, its colour sometimes revealing spider web like details. This colourful gemstone is often cut as beads and looks wonderful juxtaposed with lapis and gold.



Fabled to have magical healing powers, amber originates from the resin of bark, exuded from the bark of trees millions of years ago. Small plants, animals and even extinct species, may be fossilised within, revealing fascinating ecology of ancient forests. With a resinous lustre, this gemstone makes a delightfully delicate adornment especially as earrings where large stones weigh little on the ears.



Taken from the Greek word “amethystos”, meaning sober; amethyst quartz has illustrious calming properties, protecting wearers with a sense of tranquillity and soberness. Famed for its regal deep purple colour, February’s birthstone is said to enhance your focus and open your mind to critical thinking and clarity, and to also protect from inebriation. It is often worn by bishops set in a ring. Most are sourced from alluvial deposits in Brazil, Madagascar, Zambia and Uruguay, and Cassandra likes to juxtapose their splendour with rubies and aquamarine, or even green African garnets.

Roi Soleil Large Necklace Pendant Yellow Gold - Lilac Amethyst and Diamond



Discover the beauty of vibrant apatite, imbued with colours of the ocean. This mesmerising gemstone has an extraordinary transparency, like crystal clear waters, which will turn from green to vivid blue, with a relatively low hardness these stones are fragile and are best set in pendants or earrings.

Finita Stud Earrings 18ct White Gold - Apatite



Traditionally aquamarine, meaning ‘sea-water’, is believed to protect seafarers on voyages far away, as a gemstone saturated in the mystical blue and green colours of the ocean. Synonymous with the month of March and the surge of spring; it embodies hope, good health and new friendships. Suffused with iron, the beryl crystal lattice varies the intensity of their colours, from sky blue to colourless hues, with the most important deposits being found throughout Brazil and Africa.

Katie Oval Engagement Ring 18ct White Gold - Aquamarine and Diamond


Aventurine Quartz

Distinguished by its adventuresence, aventurine quartz contains inclusions displaying green mica crystals, creating a glittering green appearance. It is difficult to find fine quality aventurine and when it is cut as beads the wonderful green colour can be enjoyed as a necklace.

Gemstone Egg - Aventurine



A deep green stone with a crimson red flowing through this healing stone, it is sourced predominantly from India. In the middle ages, bloodstone was attributed with special powers, the red splashes symbolising the blood of Jesus Christ. Bloodstone is often used in signet rings and cufflinks where it can be die sunk or carved with initials or crests.

Agricola Signet Ring Yellow Gold - Bloodstone



The ancient Egyptians called Cornelian “the setting sun”. In its orange hues, Cornelian was worn by ancient warriors to stimulate courage. Cornelian is part of the chalcedony family and can be facetted, cut in cabochon or cut as beads.


Chrome Diopside

A rarely known gemstone, chrome diopside gleams in brilliantly vivid, bright green hues, a feature caused by the chromium element within it. A calcium magnesium silicate, with a relatively low hardness, it is best set as a pendant or earrings to avoid being scratched. Some stones have mesmerizing chatoyancy and asterism, as well as being magnetic.

Sunflower Necklace Pendant Yellow Gold - Chrome Diopside



Found in Israel, the Congo and all over the world, Chrysocolla displays hues of lapis blue and green and is often found near deposits of malachite and azurite. A gemstone of empowerment and of unique colouration. Cleopatra was known to carry Chrysocolla with her.



The Greek for golden apple, Chrysoprase is found in Australia. With its bright green body
colour, caused by nickel, Chrysoprase is a highly sought after Chalcedony for its unique colouration and its rarity to obtain large crystals. This colourful gemstone can be cut in cabochon or as beads, where the vivid apple green hue is very striking.

Pelota Necklace Yellow Gold - Chrysoprase



Drawing from the French word “citron”, lemon, a citrine gemstone emulates the vitality and freshness of the vivid yellow fruit, as a symbol for prosperity, success, and imagination.

Burnished in shades of yellow, from clear glistening yellows to flaming oranges, they are thought of as gemmologist’s gold. Pale stones remind Cassandra of white waterlilies, the brighter yellows of tumbling Banksiae roses, and the golden richer hues of autumnal dahlias. Natural citrine can be found in Brazil, Spain, and Madagascar. As November’s birthstone, they are said to protect against evil thoughts, stripping away your negativity with a new-found zest for creativity and exciting pursuits.

Carrelino Necklace Pendant Yellow Gold - Citrine



Precious coral, in a palette of soft oranges and reds, ranges from opaque and waxy to translucent and vitreous. Originating from marine environments, this is one of the most ancient of gems, with its unique concentric structure like a spider’s web. Found in Celtic tombs from the Iron Age, one of the seven treasures in Buddhist scriptures, and thought to be a powerful talisman, it has a rich and fascinating history.

Persephone Bangle Yellow Gold - Coral



One of the most renowned and romantic stones of all, the diamond has a rich and sparkling history. A symbol of eternal love famed since ancient Greece, etymology denotes that the word diamond comes from the Greek ‘Adamas’ meaning unconquerable, and so it is, as the hardest of all gemstones. The birthstone for April, these jewels are believed to increase energy, detoxify the body from impurities, and bring you inner courage. In shades varying from colourless, pale yellow to green, red, pink and blue, diamonds are found in lots of colours across South Africa, Australia, as well as Namibia, Russia and China. The most prized, pure diamonds are colourless and all are composed entirely of carbon.

They are graded by the 4 C’s, carat weight, colour, clarity and cut. Diamonds are faceted to display a unique combination of this adamantine lustre and fire, displaying a higher degree of dispersion than any other natural colourless gemstone. A high degree of skill is required to ensure precision, proportion, and precise facet edges, as well as sharp scintillation. A popular cut is round brilliant, with 57 well-proportioned facets to show off the optical effects of brilliance and dispersion, but there are other cuts including square, pear, marquise and oval.

Roi Soleil Small Necklace Pendant 18ct White Gold - Diamond



Emeralds are the most precious gemstone in the beryl crystal group, famed for their spectacular green hues, unlocked by the traces of chromium within their six rayed radial structure. While many stones will feature inclusions, the finest emeralds are remarkably transparent.

Honouring the Goddess Venus in Ancient Roman times, these protective gemstones are a prominent symbol for fertility, health, and wealth. Historically, the finest emeralds were found in Columbia and India, where one Maharaja was weighed in emeralds. Today, they enrapture world-over
and are the birthstone for the month of May, bringing to mind the essence of rebirth and growth, as leaves grow more plentiful, and the natural world is abundant with new life.

Heloise Engagement Ring 18ct Yellow and White Gold - Emerald and Diamond



With localities varying from Derbyshire to China, Fluorite displays a variation of colour and transparency. Fluorite has a crystalline structure and displays fluorescence under UV light, opening the lens to a variety of colours. Shades of green and purple can be reminiscent of tourmaline but with perfect cleavage it must be worn with care.



Originating from the Latin name “granatus”, meaning seed-like, rounded garnet crystals bring to mind perfectly polished pomegranate seeds.

The scientist in Cassandra has always been fascinated by this isomorphous series, giving rise to gems ranging from colourless through to all colours of the rainbow.

These gleaming gemstones have a high refractive index, perpetually emitting light. Some will even change colour, appearing bluish green in daylight and purplish-red in incandescent light. No wonder they are said to have guided travellers throughout history, with their light warding off all darkness and fears. With these strong associations to illumination, it’s not surprising garnets have also been so popular with kings and queens, vikings, and knights. Imbued with eternal happiness, health, and wealth, the traditionally resplendent red colour of garnets enriches wearers with faith, stability, and courage. An appropriate birthstone for January, which marks the beginning of the year.

Klover Medium Flower Pendant Yellow Gold - Garnet



Vitreous iolite stones appear in deep blue shades, enrapturing admirers with their strong pleochroism, an optical phenomenon that makes the gemstone appear to have different colours when observed from different angles. With these strong polarising effects at varying angles, it’s said vikings harnessed the stones’ powers to determine the position of the sun on overcast days.

Mashrabiya Trellis Square Drop Earrings Yellow Gold - Iolite and Diamond



Considered in Chinese culture to be the most notable of gems, jade is believed to possess magical properties that banish evil, protect, and preserve. Often used in carvings, this stone has an incredibly tough interlocking structure, but also a subtle beauty, its green shades ranging from pale hues and deep greens, to mottled green, purples, and whites.

Nephrite jade gleams in an array of dark green to brown and black shades. Found within metamorphic rocks, the mass can be several metres thick, made up of interlocking masses of microscopic fibrous crystals making it a very tough material. Its use in China extends back over 7000 years and is said to calm the nervous system and constructively channel your passions and emotions.

Temple of Heaven Earrings 18ct White Gold - Black Jade and Diamond



The best-known variety of the spodumene family, Kunzite is named after the geologist Dr Kunz who discovered this lilac-pink gemstone in 1877. Kunzite’s soft pink colouring is due to the trace amounts of manganese found in the gemstone. Kunzite crystals are often quite large, with minimal inclusions. However, due to its two cleavage directions Kunzite can be difficult to cut.



Cassandra favours lustrous blue kyanite shades for her designs, but this interesting stone also comes in shades of greens, yellows, whites, and pinks, all gleaming with a bright, vitreous lustre. Many of the stones have a central band of strong colour and are typically found as blade-like crystals. Like apatite, kyanite has perfect cleavage and should be handled carefully, best made into necklace pendants and earrings.

Rivière necklace Pendant 18ct White Gold - Kyanite and Diamond