Gemstone Guide

A gemstone is a naturally occurring mineral crystal that will have formed over millions of years. When cut and polished, they are frequently used in jewelry. Some organic materials which are used in jewelry can sometimes be referred to as “gemstones,” although strictly speaking, this is incorrect.

A gemstone is a piece of mineral crystal and when cut and polished, can be used in gemstone jewelry. Precious stones rarer than diamonds are: The Intense violet-blue hues of tanzanite, the bright electric green of imperial jade- jadeite, alexandrite from Russia’s Ural Mountains, brightly saturated blue-green hues of paraíba tourmaline, iridescent ammolites, soft velvety, saturated blues of Kashmir sapphires, natural pearl, the red variety of beryl, and dark to saturated sapphire blue of the benitoite gem.

The rarest gemstone is Painite which was first discovered in 1951, and recognised as a mineral in 1957, by a British gemologist called Arthur Charles Davy Pain. Extremely rare, for many years there was only one example of this dark red crystal, and it was on display in the British Museum in London.

Many minerals form beautiful crystals, but the most prized of all are gemstones. For example, diamonds are made up of carbon atoms which are the hardest natural substance found on Earth. Rubies are formed of a mineral called corundum, comprised of aluminium oxide and a mineral called beryl is responsible for forming emeralds which is a result of a complex mix of beryllium, aluminium, silicon, and oxygen.

Real gemstones are becoming increasingly difficult to identify due to the increased quality of synthetic stones. An expert will check the smoothness of the surface with natural stones having a slightly rough texture. They will also check the malleability (hardness) of the stone and its hue against detailed, official descriptions of different minerals.

Gemstones are nature’s gifts that form in the earth. They can only be extracted via mining which can be an expensive operation. As natural gemstones are becoming more scarce, their value is increasing.

Gemstones that are considered most valuable are Tanzanite, Black Opal, Musgravite, Red Beryl, Alexandrite, Emerald, Ruby and Diamond.

You will see in the gemstone buying guide that there is no set price range for colored gemstones. Prices may vary depending upon the quality and other factors. For Ruby, Emerald and Sapphire gems, as the quality and size of the gems increase, so too does the cost, as a buying guide will reveal.

Have a look at the different aspects of the gem, such as the color, clarity, size, hue, tone and cut shape to categorize your stone. See our guide to gemstone colors. Check the GIA’s colour wheel with 31 hues to narrow down your options.

Gemstones are naturally occurring mineral crystals that will have formed since ancient times in the crust of the earth. They need to be extracted through a mining process.

Yes, you will see in the buying guide that they can very extremely expensive, especially rare stones like Tanzanite, Black Opal, Musgravite, Red Beryl, Alexandrite, Emerald, Ruby and Diamond.

Gemstones do not have an expiry date.

Rare gemstones like the red diamond can fetch over $1 million per carat and there are less than 30 red diamonds found in the world.

The April birthstone of a diamond is the most expensive stone.

The practice of assigning birthstones goes back to biblical times. It is believed that the 12 gemstones on the breastplate of Aaron are consistent with the 12 tribes of Israel. But in the 1st and 5th centuries CE, these gems were linked to the zodiac signs.
Here is the birthstone guide, in both the traditional and modern lists:
January – Garnet. The garnet is both traditional and modern January birthstone
February – Amethyst. Amethyst is also in the traditional and modern list.
March -Aquamarine. In the modern list, it is aquamarine, while bloodstone is the March traditional birthstone
April – Diamond, in both traditional and modern lists.
May – Emerald, likewise listed in the traditional and modern.
June – Pearl in the traditional list. In the modern list, the pearl has been replaced by gem world newcomer alexandrite.
July – Ruby, in both the traditional and modern lists.
August – Sardonyx in the traditional list. Peridot in the modern list. Recent listing shows the spinel as an option to the peridot as the modern August birthstone.
September – Sapphire, in both traditional and modern listings.
October – Opals in the traditional list and tourmaline in the modern list. The tourmaline has many varieties. There are also multicolored tourmaline stones.
November – Topaz is both the traditional and modern November birthstone, but recently Citrine is a modern option.
December – Traditionally, turquoise and lapis lazuli while modern listing shows tanzanite, blue topaz and blue zircon as alternatives.

Some tips from popular gem and jewelry companies:
Treated gemstones are not “fake” and are different from synthetic gemstones. …
There are many types of treatments specific to the type of gemstone. …
Treated stones are less expensive than untreated stones.
Natural, untreated gemstones are not always “the best.”
Nowadays, it is considered a safe practice to request a lab certificate for above $1000 purchase of ruby, sapphire, or emerald.

The best or surest option would be to consult a gemologist for the quality of your gem. You can also look for cracks, scratches or black spots inside the stone – you can do this by passing a pen light across its surface. Also, observe color changes when the stone is in natural light, incandescent light and fluorescent light.

Opaque gemstones are usually made into cabochons (shaped and polished into a dome at the top and flat at the bottom). More transparent gemstones are mainly faceted. Cabochon cuts often vary in depth and proportions.
One gemstone that is rarely made cabochon is the diamond (especially for a ring) because faceting reveals its beauty in finely balanced proportions.