(Emeralds are the highest value gems found in Aghanistan)
If you are intending to make a more substantial purchase, don't be afraid to ask for a small sample (for which you may have to part with a small amount of cash) and have the stones carefully assessed by a reputable gemmological laboratory. Even an honest seller can sometimes be taken in by a scam himself so it pays to be certain. If the vendor refuses to allow you to do this, it may be worth considering walking away from the deal. There is no substitute for a microscope and a qualified gemmologist with lab equipment in determining the provenance of a stone. It is important to remember that the rules which apply to one gem do not necessary apply to another and some gemstones attract greater levels of fraud than others, due to the relative ease with which synthetic substitutes, enhancements and treatments can be used. Around mine heads a process known as 'salting' can often take place whereby synthetic stones are fused with natural stones at the point of production to exaggerate the dimensions and carat size they purport to be. Conversely, some gems do not have readily available or inexpensive synthetic treatment, enhancement or synthetic additions options available so tend to be more prevalent in their natural state.
(Buyer beware when purchasing uncertified stones from Afghanistan)
Some prominent stones available in Afghanistan:
Tourmaline
This is true of tourmaline, as there is no synthetic equivalent of this stone in existence. Tourmaline also carries the advantage that it's clarity can be easily inspected under 10 times magnification through a loupe. The price of this gem starts very low but can rise significantly for the right depth of colour, size and clarity so try to avoid stones smaller than 5 carats rough or those with significant inclusions. Tourmaline comes in an array of colours but the most sought after are pinks, greens, blue-greens, reds and purples. As with emeralds avoid stones that are too dark or at the other extreme too light.
Aquamarine
A blue to blue-green variety of the mineral beryl, it is rare to find synthetic examples of this stone. Aquamarine is fairly easily identified as such and it's clarity can be confirmed under a 10 X loupe. When buying aquamarine always look for clean material that is dark in colour (which is not easily found in Afghanistan).
Morganite
Peach to pink in colour, this stone is a lesser known member of the beryl family of minerals and it is also very rare to find synthetic substitutes. Again it is fairly easy to inspect the quality of Morganite through a loupe and the darker stones are not usually found in Afghanistan.
Other Beryl stones
A variety of other Beryl gems can be found in Afghanistan, including golden heliodor, yellow beryl and colourless goshenite. These gemstones are very attractive but often hard to resell so they are more for collectors rather than dealers or investors.
Emerald
The 'king' of the coloured gemstone, emeralds are precious gems from the beryl family and a significant number originate in Afghanistan. They fetch the highest prices of all precious coloured gems (emerald, ruby, sapphire) and they have a large and well-established global market. Synthetic emeralds are commonplace and can only be determined from their natural counterparts by a highly skilled eye. Most emeralds are included in some way with fissures, which are commonly treated with oil or resin when they connect with the surface of the stone. The amount and type of oil applied to the stone can have a dramatic effect on the value. Due the high price of natural emeralds, coupled with the array of techniques that exist to enhance or synthesise them buyers should be careful with these gems and trust only in reputable dealers and certification authorities. Fine examples of natural Afghan emeralds are second only to the Colombian emerald in terms of quality, colour and price and they are generally considered slightly superior to most African stones.
Rubies & Sapphires
Rubies and sapphires are highly prized precious gems that are found in very small quantities in Afghanistan. Due to their extreme rarity in this country the vast majority of stones that are sold as rubies and sapphires in Afghanistan are actually synthetic.
Spinel
Pink and red spinel are produced in very small quantities in Afghanistan and it takes an expert eye to be sure the stones are natural.
Topaz & Kunzite
Significant volumes of Topaz and Kunzite are produced in Afghanistan each year to the point at which supply often outstrips demand. Topaz is notorious for colour fade over time (especially in direct sunlight) so care must be taken with this stone.
March Birthstones: Aquamarine and Bloodstone
How to tell if a diamond is real?