What you should know about Coloured Gemstones
Your desire to own or wear a coloured gemstone isn’t new or unique. Throughout all civilizations, gems have held a fascination – sometimes even a legendary power – for people from all cultures.
The mystery and romance of gemstones goes back as far as we can trace, to those early days when people coveted these beautiful stones as charms or amulets to ward off evil. Later, as life became more sophisticated, the rarity and beauty of gems established themselves as the ultimate status symbol.
Today, the pride of possessing a rare and beautiful gemstone is as great as ever.
Why purchase a coloured gemstone?
The reasons for buying a coloured gemstone are as diverse as the people who desire them.
• Gemstones are beautiful: Every stone is a natural work of art. Each one having a distinct and separate
personality and possessing unique and distinguishing beauty marks.
• Gemstones are durable: Gemstones can last for generations and, in some cases, for centuries. The treasures of King Tutankhamen prove that gemstones endure through many lifetimes.
• Gemstones are rare: While it is true that there are new rich mining sources of gemstones, today’s economy has brought higher disposable incomes to more people than ever before. As the demand for gemstones is greater, the supply has become limited in its ability to meet this demand.
Your gem may be a symbol of love, a fashion statement, or a celebration of life. Whatever the occasion, gemstones are a reflection of you, the individual. They are gifts that are as beautiful and rare as the person they adorn.
Choosing a gemstone
What are the factors that make a gem rare and valuable?
Much like a diamond, the various combinations of a stone’s colour, clarity, cut and carat weight along with availability and accessibility determines rarity.
Colour: Colour is typically the most important value-setting factor for gemstones. All gems have a preferred colour, or a relatively small range of preferred colours. The more the colour varies from this range – whether lighter or darker, more vivid or less – the less valuable the stone.
Colour is composed of three dimensions: hue, tone, and saturation.
• Hue refers to the impression colour usually noticed immediately, such as red, orange, yellow, green, blue and violet.
• Tone refers to the degree of lightness or darkness of an object, for example, a range of blue from light to dark, with numbers 0 – 10. 0 is so light as to be colourless (or white), and 10 is so dark it is black.
• Saturation defines the degree of purity of a hue. The terms “strength” and “intensity” also refer to this characteristic. The higher the proportion of pure colour, the higher the saturation. Colour saturation is divided into 6 levels. Level 1 is showing a strong undertone of grey (cool colours) or brown (warm colours) and is termed “Grayish” or “Brownish”. Level 6 is a pure “Vivid” saturation.
Clarity: A gemstone’s clarity grade is directly related to its rarity. Clarity refers to a gemstone’s relative freedom from clarity characteristics. Clarity characteristics include inclusions, which lie within the stone, or blemishes, which lie on the surface of a gem. The fewer clarity characteristics, the more rare the gemstone. Each variety of a gemstone has its own clarity standards. For example, Tanzanite is virtually inclusion-free while Emerald almost always contains clarity characteristics. For this reason, Gemological Institute of America’s grading system divides transparent coloured gemstones into three clarity types. This allows gems to be more evenly evaluated, as it takes into account the individual nature of each gemstone.
Each type is further divided into five grading descriptions. Gemologists will first consider the gemstone type and then consider the size, location, number, nature and colour of the inclusions before assigning a clarity grade to a gemstone.
Clarity Types
Type 1 gems are often virtually free of clarity characteristics. The stones most commonly seen include:
Aquamarine Green Tourmaline Kunzite Tanzanite Topaz- Blue Zircon- Blue
Type 2 gems normally contain clarity characteristics. The stones most commonly seen include:
Andalusite Alexandrite Amethyst Ametrine Citrine Iolite Peridot Ruby Garnets- all species and varieties Smoky Quartz Sapphire- all colours Spinel- all colours Tourmaline- Pink,Blue,Red,Orange,Yellow and Parti-coloured Zircon- Green,Orange,Red,Yellow
Type 3 gems almost always contain clarity characteristics. These include:
Emerald Tourmaline- Watermelon
Clarity Grades
| Type 1: Usually eye clean with no clarity characteristics visible to the unaided eye. | Type 2: Typically shows some eye-visible characteristics that do not detract from the overall beauty of the gem. | Type 3: Almost always contains eye-visible clarity characteristics. | |
| Eye Clean | Appears clean to the unaided eye. | Appears clean to the unaided eye. | Appears clean to the unaided eye. |
| Slightly Included | Minute inclusions difficult to see with the unaided eye. | Minor inclusions somewhat easy to see with the unaided eye. | Noticeable inclusions apparent to the unaided eye. |
| Moderately Included | Minor inclusions somewhat easy to see with the unaided eye. | Noticeable inclusions apparent to the unaided eye. | Obvious inclusions very apparent to the unaided eye. |
| Heavily Included | Prominent inclusions that have a negative effect on appearance or durability. | Prominent inclusions that have a negative effect on appearance or durability. | Prominent inclusions that have a negative effect on appearance or durability. |
| Severely Included | Prominent inclusions that have a severe effect on appearance, durability, or both. | Prominent inclusions that have a severe effect on appearance, durability, or both. | Prominent inclusions that have a severe effect on appearance, durability, or both. |
Cut: Cut refers to the shape or design of a stone, as well as the precision of the stone’s proportions and finish.
The cutting process reveals the beauty of the gem.
Gemstones are facet-cut or cabochon-cut into shapes we are familiar with such as oval, emerald, pear, marquise, round, princess, heart and other.
In addition they can be carved or artistically cut into almost any free-form design imaginable. Here an Aquamarine cut by Alexander Kreis, one of my favourite modern gem cutters.
Proportions involve the balance and appeal of the basic design. Finish refers to the details of the workmanship. A well proportioned cut with a fine finish will show a stone’s optical properties to its fullest potential.
When all factors are even (colour, clarity, and carat weight), a better-cut gem will be more valuable.
Carat: Gemstones are weighed in units of measure called “Carats”. One carat is divided into 100 ‘points’, so the weight of a gemstone of 50 points is 0.50ct, or half a carat. A carat is equal to one-fifth of a gram.
Up to a certain point, the larger a stone is, the more rare it is and the higher the price it will command. For stones that commonly occur in larger sizes, the value may decrease if the gem reaches a size that makes it impractical for jewellery use.
How to discover “The World of Colour”
What is a coloured gemstone?
Most simply stated, the majority of gemstones are minerals (important exceptions – pearls, corals, amber). These minerals have been crystallized as a result of high temperature and pressures exerted by nature on the elements that form the earth’s crust.
Of more than 3,000 minerals found on earth, only a small percentage qualify as gemstones due to their beauty, durability and rarity. The most sought after are transparent gems, drops of pure colour cut from single crystals. They were once divided into “precious” and “semi-precious” categories.
This is no longer true as gem discoveries have added new varieties to the traditional selection of ruby, emerald and sapphire. In fact, some of the more unusual gemstones command higher prices because of their beauty and rarity.
The selection of fine quality gemstones includes such stones as alexandrite, amber, amethyst, aquamarine, chrysoberyll, citrine, garnet, iolite, jade, kunzite, lapis lazuli, moonstone opal, peridot, spinel, tanzanite, topaz, tourmaline, turquoise,and zircon. Each of these gemstones has a particular charm, colour and identity.
Colour: Gemstones produce some of the finest and most durable colours. For a jewellery designer and colour-lover like Juerg P. Muff, the truly amazing green shades of an Emerald, the azure depths of an Aquamarine, the kiwi-green succulence of a Peridot, the flaming sunset like oranges of a Fire Opal or the passion of a fiery red Ruby are a sheer delight. When carefully set in a finely crafted piece of jewellery, the beauty of these colours can be absolutely irresistible.
Juerg can offer you guaranteed natural colour gemstones. These rare gems are of natural colour and clarity, untreated by man, just the way nature intended them to be. From lavenders to fresh peach to vibrant pinks (fancy coloured sapphires), lush greens (peridot, tsavorite), velvety reds to crimson pinks to warm golden hues (pyrop and rhodolite garnets, precious topaz, spessartite), azure to deepsea blue to purplish blue (sapphires, iolith) they are available in a rainbow of colours. Juerg prefers these gemstones for their natural beauty.
Rarity: The various combinations of colour, clarity, cut and carat weight are the primary factors in determining the value of a gemstone.
Some other factors that impact rarity are the abundance of a particular gem type, and the geographic location where it is mined. Several gemstones are more abundant and are more easily accessible than others. The science of geology explains why some gems are more common than others:
Quartz (citrine, amethyst etc.) is composed of silicon and oxygen, SiO2. Silicon and oxygen compose 74% of earth. So, you understand why quartz is one of our most common minerals. On the other hand, Corundum (ruby, sapphire etc) consists of aluminum and oxygen, Al2O3. These are common elements and corundum itself is quite common. The emery on your sandpaper or nail file is corundum. However, it takes the addition of chromium to make a ruby. Chromium is one of the rarest elements in the earth.
Many other gems are found in remote locations, which makes mining virtually impossible. The economic and political environments of the region where the gemstones are located may also limit the accessibility of some gems.
With all of these considerations, it is truly an amazing and often challenging journey from the mine to the goldsmith.
The gem you will choose is a treasure – rare, beautiful and valuable: just like you!
Caution: There are now a number of ways that gemstones can be artificially “created”. These laboratory created materials duplicate their natural counterparts. While natural and man made materials can share the same physical and optical properties, there are still considerable differences, the main one being rarity. A natural gem takes considerable time to form and is usually millions of years old. Plus, many feel they have aesthetic qualities not found in mass produced materials.
The majority of these “synthetics” are sold through the Internet and are typically offered at significant savings.
Confidence: Knowledge of the gemstone industry and the nature of gemstones requires years of extensive study. Therefore it is absolutely vital that you purchase your gemstones from a reputable jeweller, one that you can trust.
Juerg P. Muff is a Swiss trained jeweller with over 35 years of experience and contacts in the gemstone world. He operates an established “brick and mortar” jewellery business in New Zealand, is a member of the Jewellery Manufacturers Federation of NZ and the Gemological Association of New Zealand.
Juerg constantly sources and imports gemstones direct from around the globe.
Your Guarantee:
In a desire to preserve the natural beauty of each coloured stone, Juerg P. Muff seeks only natural gemstones.
All coloured gemstone engagement rings are supplied with a complimentary independent valuation.
Juerg says: “I am aware that this might be one of the most important purchases you will ever make. I will endeavor to source you the gemstone you are looking for, be it a pure drop of colour for your ring or pendant, an investment stone for you to treasure or a birthstone to celebrate a special occasion. According to your budget and specifications I will personally guarantee to supply you with the very best gemstone your money can buy. Making this your Gem of Colour.“
~ Juerg P. Muff (Diamond Grading Cert. GAA)
For a gemstone picture gallery and more information visit www.gemstone.org/gem-by-gem
**The criteria for gemstone grading, most applied internationally, was developed by the Gemological Institute of America (G.I.A.). The terminology and systems described on these pages are based on those of the G.I.A. However, while the G.I.A. system is the most used, instituting it as a standard has been strongly renounced by the coloured stone industry. Coloured stone grading is too complex for a simple system as it is used with diamonds.
Source: G.I.A., I.G.A., JWNZ, B.I.C. Lotus Gems, ICA
