Amethyst Gemstone Guide – Price, Quality Factors & More!
Amethyst is the most well-known and desirable Quartz variety, it is not surprising that it is a very popular gemstone due to its low price, beautiful colour and significance both historically and in the modern world.
If you want to learn more about Amethyst, then you have definitely come to the right place as in this post, I’ll go through all the things you need to know about this stunning gemstone.
Amethyst Properties
Let’s start with some of the properties of Amethyst and by properties, I mean its physical and gem properties:
Amethyst Formation and Origin
Natural Amethyst forms when silica-rich hydrothermal solutions (hot, mineral-rich fluids) that also contains iron, finds its way into cavities or voids in existing rocks, usually through cracks and fissures.
Then, over a long period of time, this liquid begins to cool and evaporate, which allows the silica and iron to begin to solidify and on the walls of the cavities, Quartz crystals start to grow but in order for the iron in the crystal to produce that beautiful purple colour, it needs a helping hand.
This comes in the form of natural irradiation, which affects the iron at an atomic level and creates what are known as colour centres, which absorb light at specific wavelengths and gives Amethyst its beautiful purple colour but don’t worry, Amethyst isn’t radioactive!
Where Is Amethyst Found?
Amethyst is found in many places around the world, including:
One historically important source is Siberia (Russia), this was known for producing some of the finest Amethyst and although it is now pretty much mined out, its legacy lives on as very fine quality Amethyst is often referred to as Siberian Amethyst, even if it didn’t come from there.
Amethyst Price and Quality Factors
Due to the abundance of Amethyst, the price range isn’t that big with lower quality stones costing as little as $1-$2/ct and high-quality Amethyst costing up to $50/ct but what are the factors that influnce the price?
Colour
Colour is one of the biggest quality factors when it comes to Amethyst, not surprising for a coloured gemstone!
There aren’t any official classifications for colour in Amethyst (ignore any A, AA or whatever rating sellers put on their stones) but you will often see the colour described as:
- Light – this is where the purple is very light and almost lavender in colour (not to be confused with Lavender Quartz)
- Medium – these stones have a darker body tone and a much stronger purple colour, when cut right, these colour stones can really pop
- Dark – these are the stone that have that really deep, rich purple colour and these are the most desirable
Generally, the darker the stone, the more valuable it is, with the exception of very dark Amethyst, as these start to lose the purple colour and can look almost black in certain lights.
Other undesirable features include any brown or bronze tints within the stone and any noticeable colour zoning when looking through the top/crown of the stone.
Clarity
Unlike many more expensive gemstones, clarity isn’t that big of an issue when it comes to Amethyst, this is because:
Due to the large amount of high-quality crystals from a clarity perspective, the majority of faceted Amethyst will be eye clean and in some cases, loupe clean. Obvious inclusions are quite rare in faceted stone, with the most commonly seen inclusion being angular colour zoning (from my experience).
Crystals that have some inclusions but good colour will often be fashioned as cabochons or possibly even left as crystals.
Lower quality, heavily included Amethyst is usually used for ornamental pieces or carvings, especially if it has a nice purple colour.
Cut
Unfortunately, due to the low price of Amethyst, the majority of faceted stones are cut to a commercial quality, which means that the stones look attractive to the naked eye but under closer examination, you may find some imperfections, such as:
- Misaligned facets
- Polishing marks on facet faces
- Imperfect outlines
- Proportions are not quite right
You may come across stones that has been precision cut but these sell for a much higher price than most commercially available Amethyst due to the time required cutting the stone to a high standard.
In terms of cut styles, the majority of faceted Amethyst are ovals, rounds or octagonal (emerald) style cuts.
Most oval and round Amethyst will have a conventional crown style (a table and crown facets), it isn’t unusual to see checkerboard style crown (lots of smaller diamond-shaped facets) or buff top (a polished dome, similar to the way a cabochon is shaped).
It isn’t uncommon to see pear, square or marquise cut stones but care needs to taken with these styles of cut as the points on the stone are a weak point and prone to chipping or breaking.
For cabochons, ovals and rounds are by far the most common.
Carat
Carat weight doesn’t have a huge impact on the price of Amethyst but generally, the bigger the stone, the higher the price until you start to get towards really big stones (30/40 carats plus) that aren’t really usable in jewellery.
At that point the price per carat can start to fall as there is less demand for them and it is usually people like me who buy them just because it is fun to have some stupidly large gemstones!
You will often see that Amethyst are sold by the size of the stone rather than the weight, this is because prices don’t jump at certain weights (1ct, 2 ct etc) like they do with more expensive stones, for example, you aren’t going to pay more for a 12x10mm oval that weighs 4.4 carats than a 12x10mm oval that weighs 3.6 carats.
Amethyst Treatments
This might sound contradictory but Amethyst is rarely treated but also commonly treated, let me explain!
Pretty much all the Amethyst on sale, whether faceted, cabochons or crystals, hasn’t been treated. This is because Amethyst is abundant and available in all different qualities to satisfy the market.
But on the other hand a lot of Amethyst is heat-treated to create other Quartz varieties, mainly Citrine but also Prasiolite (this only happens to some Amethyst from Brazil).
I hope that clears that up.
How To Identify Amethyst
How do you find out if the stone you are looking at is Amethyst? Well, there are a few simple tests that can help you find out but you will need some gemmological tools in order to be able to do this.
This is the process I go through to see if a stone is an Amethyst or not:
These tests should tell you whether or not the stone is Amethyst. I personally don’t bother using any other tools as they don’t help with identification.
Natural vs Synthetic Amethyst
The next logical step after identifying whether you have an Amethyst or not is to identify whether it is natural or synthetic right?
The problem is that telling the two apart is very difficult as natural and synthetic stones give the same results on all the standard gemmological tests and there are rarely any obvious inclusions, especially in faceted stones.
One inclusion that can indicate the stone is natural is if you see angular colour zoning, as this is usually absent in synthetic stones (I say usually as it isn’t 100% guaranteed) but this isn’t present in high-quality stones.
So how do you find out for sure? By sending it to a reputable gem lab but the problem is that the cost of finding out whether the stone is natural far outweighs the cost of the stone and the difference in price between natural and synthetic (which is minimal).
Caring For Amethyst
You want your Amethyst looking the best it can for as long as it can and whether you have a faceted stone, cabochon or crystal, there are a few things you can do to look after your stone.
Amethyst in Rings
Amethyst is a popular stone in rings due to its beauty and also being a birthstone etc but care needs to be taken and ideally, shouldn’t be worn every day (I don’t recommend Amethyst for engagement rings!), but why?
- They can scratch and chip quite easily
- They can break and fracture easier than some other gemstones
They are fine for rings that are worn occassionally, such as cocktail rings but the wear and tear of being worn day in, day out soon takes its toll and I come across a lot of Amethyst and it is easy to see which ones were in rings and which ones have been in pendants or earrings.
Cleaning Amethyst
The simplest and safest way to keep your Amethyst jewellery looking its best is to use a bowl of warm water, some hand soap (less abrasive than washing up liquid/dish soap).
Place the piece in the bowl for a few minutes, then use a soft-bristle toothbrush to remove any dirt, then rinse under clean water and dry with a clean cloth.
Most faceted Amethyst will be fine in an ultrasonic cleaner but care should be taken if the stone has fractures, as the ultrasonic waves can make these worse and in some cases, cause the stone to break.
For crystals, you can simply rinse them under clean water to remove any dust, for clusters, you can use a soft-bristled brush to get into tighter areas but I generally recommend keeping them in some type of display case to stop them getting dusty in the first place.
Fading
This only really applies to crystals as it is very rarely that faceted stones or cabochons will be left in direct sunlight for extended periods of time.
But crystals often do as they are often be left on window sills, desks or bookcases as a display piece and will often be exposed to direct sunlight on a regular basis and over time, the crystal will begin to fade and what started out as a deep, rich purple crystal ends up as a pale lavender colour.
So don’t leave your Amethyst crystals in direct sunlight, by all means display them but make sure it is in a sheltered place to keep your crystal looking like it did the day you bought it.
I'm Paul Haywood FGA DGA, the owner and founder of Haywoods Gems, I'm a fully qualified Gemmologist and Diamond Grader from the Gemmological Association of Great Britain.
