Why Is Amethyst Purple ? The Surprising Way Amethysts Are Made

Amethysts are beautiful gemstones that have been around for millennia, and for a long time it was considered as desirable as ruby, sapphire, and emerald ! Amethysts were a royal stone all the way until the 1800s when a large vein was discovered in Brazil.

Still, having a deep purple gemstone in your jewelry set is nothing to sneeze at, especially since amethyst was considered a royal color. So what gives amethyst its beautiful color ?

amethyst purple

Why is amethyst purple ?

Amethyst gets its purple color from trace amounts of iron within the crystal, and a very specific gamma radiation range. As the amethyst forms, the surrounding rocks have to irradiate the crystal and the iron atoms replace silica atoms within the crystal. 

When you look at an amethyst geode, you’ll dee the base of the amethyst is white (or clear) and the purple gets progressively darker as it reaches the tips. This is due to the slow but sure irradiation from the surrounding rock.

This does not mean amethysts will irradiate you, however it does mean they can easily be manipulated through radiation and heat (color-wise).

The reason you’ll notice different shades of purple is because not all of them are fully irradiated, and not all geological sites produce gem-quality amethyst. The best amethyst is a deep purple color with red flashes. This effect can be easily tested if the stone is cut properly.

Is amethyst always purple ?

Yes, amethyst is always purple and it may be different shades of purple, depending on how it grew within the bedrock. In truth amethyst is a type of quartz, and only the purple quartz may be considered amethyst.

Other quartz colors are:

  • smoky quartz, ranges from almost clear to dark grey-brown, very clear with smoky bands
  • morion, a nearly black version of smoky quartz
  • blue quartz, non-transparent alternating light and dark blue streaks
  • citrine, a yellowish-brown crystal, smoky or cloudy
  • ametrine, amethyst and citrine that have grown within the same crystal and have a yellow to purple fade
  • rose quartz, a cloudy pink crystal that ranges almost to rose red
  • prasiolite, a light green crystal very rare in nature; commonly an induced crystal made by subjecting pale amethyst to high heat and radiation in an attempt to produce citrine

Read also: Yellow Gold VS White Gold

What is the rarest color of amethyst ?

The rarest color of amethyst is the deepest shade of purple with red flashes. This is the most desirable color and one not often achieved by most amethyst stones. As they grow in nature, they form under various temperature and radiation levels, thus leading to some very different shades of purple.

Does amethyst fade in the sun ?

Yes, amethyst can fade in the sun if left out for too long. Some stones can fade within a few hours, some may fade in a few weeks. The fading is triggered by solar radiation, the same radiation that bleaches color out of your curtains.

There is no way of knowing which amethyst will fade fast and which not, so it’s best to protect all your amethysts. You can do this by simply not exposing it to bright, direct sunlight especially in the summer time when the Earth is closer to the Sun.

You can either store the amethysts in a jewelry box or opt to cover them with a thick cloth that will not let sunlight pass through

If you’re wearing jewelry that has some amethyst stones in it, repeatedly exposing it to sunlight may fade it, but the occasional wear won’t hurt it too much.

Why is amethyst so cheap ?

Amethyst is cheap because of two reasons. First, almost all amethyst on the market is not natural, it is lab-grown and it’s very difficult to tell it apart from the natural one without very expensive tests. So all amethyst are priced lower, by default.

And the second reason is that back in the 1800s a very large deposit was found in Brazil, and the supply became greater than the demand. This mead to lower, more affordable prices for amethysts.

Amethyst substitute

If you’re on the market for a gemstone that is a beautiful shade of purple, but don’t really want to go for an amethyst, there are a few options. Some on this list may have a higher price point than amethyst, since amethysts are usually affordable.

Keep in mind that purple is not a common color when it comes to gemstones, and most of these are variations on the more common stone color. Some may be heat treated to get a deeper color, or to induce a certain shade or purple. If that’s something you don’t want be sure to ask the jeweler before buying.

Purple diamonds, very rare

Purple diamonds are some of the rarest versions of diamond, right along with bred diamonds. Being diamonds they’re very clear so their overall color is similar to a light amethyst. 

And being diamonds, and rare ones at that, these are some of the most expensive ones you can get your hands on. They’re also very tough and will resist any scratch or damage.

Iolite, common yet very beautiful

Iolite is a beautiful bluish purple and it’s actually easy to get a hold of. You don’t hear about it very often simply because it’s not the flashiest out there. But with the right cut and polish it will give you a beautiful piece of jewelry. And since it’s affordable you can even use several at a time.

Purple tourmaline, a reddish purple

Tourmaline comes in a wide variety of colors, perhaps the most well-known being the pink and green version that resembles a slice of watermelon. 

This stone is very clear and not smoky, so the overall color will be a reddish purple that may appear very light sometimes. The reddish hues are often induced or enhanced by heat treatment. So if you’d rather a cooler hue, ask for one that is untreated.

Purple spinel, pinkish-purple

Not much is known about this gemstone but it comes in various colors, and you can easily find it in different shades of purple. It’s translucent, like amethyst, not cloudy or opaque.

Purple sapphire, pure violet

Purple sapphires aren’t around every corner, but they can be found as easily as regular sapphires. They actually come in a variety of colors, including yellow, green, brown, orange and yes, purple. Like diamonds sapphires are very durable and can withstand nearly anything.

Purple fluorite, smoky purple like amethyst

Fluorite comes in many different colors, much like quartz. You can get it in almost any color, so you can easily find it in purple. Keep in mind that this is a very soft, breakable gemstone (4 of 10 on Mohs scale). You will need to use a very protective setting for it.

Choose a protective fitting for softer stones

When you choose your stone, be sure to ask about its hardness. How hard a stone is dictates how easily it will break if it falls out of its setting, how easily it scratches, whether it has a change of splitting while working with it and so on. 

Some stones like diamonds and sapphires are especially durable and they will withstand anything. Other stones, like fluorite have a much lower rating. 

For comparison, pure gold (24k) has a rating of 2.5, while diamond has a rating of 10. Sapphires are a 9, and platinum is 3.5.