You probably have some difficulty telling amethyst apart from fluorite, and you are not alone.
These two rocks are usually confusing because of their physical similarities.
Both are crystalline and occur in a variety of transparent and purple colors. So, what are they?
Amethyst vs Fluorite: The Facts
What is Amethyst?
Amethyst belongs to a mineral category known as quartz.
Quartz is chemically composed of one silicon atom and two oxygen atoms to form silicon dioxide (SiO2).
Purple quartz usually has a hexagonal pyramid structure.
This gemstone, a birthstone for those born in February, is similar to other forms of quartz, only that it is purple.
Historically reserved for royalty, amethyst has a color range between rich purple and light lilac.
Amethyst can be naturally mined from the ground or cultured in the laboratory under special conditions.
Both types of amethyst are used in a variety of jewelry, such as bracelets, ring additions, and necklaces.
Traditionally amethyst was given as a gift during six years anniversaries. If you want to do the same, you got a green light from us.
Amethyst History and Origins
The word amethyst originated in ancient Greek mythology.
The term “amethystos,” roughly translated, means “a cure for drunkenness.”
Greek mythology has it that amethyst was a young maiden at the receiving end of the drunk god Dionysus.
She cried to another goddess Diana who transformed her into a white rock.
Dionysus, feeling remorse for his actions, wept.
The tears dripped and overturned his goblet, which poured red wine on the white rock saturating it to the violet color.
Russia had been the leading supplier of amethyst until the 19th century, when natural deposits were discovered in Brazil.
Today, the amethyst crystals are mined in Africa and Asia, although a significant portion still comes from the southern state of Brazil, Rio Grande du Sol.
Amethyst Crystal Formation
Amethyst crystals are formed in an exciting way.
During volcanic activity, the air is trapped inside molten lava.
Silica-rich liquid flows into the bubble and triggers the formation of crystals within volcanic rocks.
And the wonders of amethyst don’t stop there.
Those gas bubbles later form huge geodes that resemble plain stone outside but are full of precious amethyst gems inside.
Some Brazilian geodes are so huge that an adult can fit inside standing upright.
Geodes take millions of years to grow from volcanic rocks.
Some of them probably started growing when dinosaurs still roamed the earth.
The formation of geodes sets amethyst apart from other gemstones like white diamonds, which don’t form geodes.
The value of amethyst doesn’t differ much from other gems.
Before you pick your bag and go amethyst shopping, we will tell you some of the common characteristics to look out for to get that deep blue cabochon.
The qualities can negatively or positively impact on quality and price of this purple gemstone.
We have already stated that purple is the primary color of amethyst.
However, the hue can range anywhere from rich purple to pinkish.
There are two color aspects which can drastically lower the quality and price of amethyst.
Being excessively dark absorbs much light instead of reflecting so that the stone appears dark and dull under certain light wavelengths.
The second aspect is color zoning.
Some bronze-colored tints can form inside the stone, drastically reducing its value.
Crystals usually have very few inclusions, usually hidden from plain eyesight.
Inclusions are imperfections in precious stones that occur during their formation.
Those originating from Brazil typically have a limited number of inclusions- the reason why they fetch such handsome prices.
You would need to look at the gem under ultraviolet light to see the imperfections.
Gems that feature visible inclusions are of poor quality and are cut into cabochons or beads.
According to gemologists, how an amethyst crystal is cut will positively or negatively affect light reflection and, consequently, prices.
Customers love something glossy and shiny.
Some of the popular cuts include triangle, emerald, cushion, oval cut, and other customized free form shapes.
The higher the carat, the larger the crystal.
This is true for the diamond but not for lilac amethysts.
Prices often vary with quality and cuts but not size.
We would advise you to go for amethysts if you are in love with larger jewelry designs.
What is Fluorite?
Fluorite is a halide mineral made up of one calcium atom and two fluorine atoms to form calcium fluoride. (CaF2)
Typically, these crystals take the form of isometric cubes, the simplest crystals system, although it is not uncommon to find other complex isometric shapes such as octahedral.
Fluorite occurs deep in the earth’s crust, usually a constituent of sedimentary rocks or felsic igneous rocks.
When hydrothermal activity occurs, vein deposits occur where fluorite acts as a cementing material for sandstone or late crystalizing material in felsic igneous rocks.
The gem, usually with a hardness of 4 on the Mohs hardness scale, can form cubic crystals up to 20cms across.
Burin Peninsula, Newfoundland, Canada, is the largest producer of fluorspar. You want to know how to tell if fluorite is real?
Scratch it with quartz.
A color competition between fluorite, garnets, rubied, and sapphire fluorspar takes the day.
Ironically the purest fluorite crystals have no color at all, but impure forms have a wide range of iridescent and brilliant color displays.
The color formation phenomenon is a result of the rock formation process over centuries.
Due to hydrothermal activities, fissures in sedimentary rock cavities are constantly opening and closing, a process that may block the entrance of vital fluorite-forming minerals.
These small changes cause color zoning as the crystals grow.
How chemical ions are bond to form the lattice also dictates the color of the crystal because impurities can infiltrate the structure, permanently altering the color.
Structural defects in the lattice also result in a color change.
Manganese impurities, for example, usually result in orange-colored crystals.
What of the deep purple hue commonly associated with these gems?
It is as a result of irradiation or heating permanently displacing some fluoride ions out of the lattice.
A single electron replaces the displaced fluoride ions in every hole, which causes color absorption and re-emission by these electrons, creating that rich purple hue.
Fluorite has some lapidary uses, such as making beads, though it is not very popular.
Fluorspar has a Mohs hardness of 4, which is way too soft for gem qualities at 7.
Fluorite, therefore, is much popular in industrial applications than beauty.
Fluorspar is mainly used in the production of hydrogen fluoride using concentrated sulfuric acid for industrial uses.
There are three fluorspar grades due to impurities, each with a different industrial application.
The most inferior quality or metallurgical grade fluorite acts as a flux and allows extraction of impurities from steel and later aluminum by lowering the melting point.
Ceramic grade fluorite is a raw material in the manufacturer of utensils, enamels, and iridescent glass.
The acid grade category is the highest in quality and produces two main fluorine compounds, cryolite, and AIF3, for smelting aluminum.
Amethyst vs Fluorite: Differences?
Amethyst gemstones are formed in geodes, a characteristic that other gems, including fluorite, lack.
Geodes are cavities made up of plain volcanic rocks that allow amethyst crystals to develop inside.
Amethyst and fluorite have different formation processes.
Amethyst forms as a result of gas bubbles encapsulating silica-rich liquids during volcanic activities.
Amethysts grow inside these rocks over millions of years.
On the other hand, fluorite is a result of the deposition of fluorine-rich fluids on felsic igneous rocks and sandstone over a couple of centuries.
Another difference is in the formation of crystals.
Amethyst forms crystals in a six-sided pyramid, while fluorite forms the simple four-sided or isometric cubes and other complex octahedral shapes.
The most obvious difference is in colors.
Amethyst rock colors range from reddish to rich, deep purple.
Purest fluorite rocks are transparent though impure forms have a wide band of colors due to impurities such as Manganese and other factors such as displacement of ions in the lattice.
Remember, amethyst is a lilac variety of quartz with a seven contrasted with a 4 for fluorine.
Quartz will scratch fluorite, so we advise you to store your jewelry separately.
Similarities between Amethyst and Fluorite
Fluorite and amethyst together are chemical compounds, amethyst being a compound between one silicon ion and two oxygen ions forming SiO2.
Fluorite is a compound between one calcium ion and two fluorine atoms forming CaF2.
Why do People Confuse between Amethyst and Fluorite?
People mainly get confused between the two due to the visual similarities.
Both rocks have similar colors.
You can get them in colorless or white tones.
You are probably familiar with their purple hue, although they can have green, blue, and pink shades due to impurities.
If you accidentally pick a gem during one of your random walks and can’t tell whether it is amethyst or fluorite, get a kitchen knife.
Knife hardness is in between the two as it will scratch fluorite and not the purple quartz.
Forget about the visible similarities- lilac quartz and fluorite are very different in many aspects.
Whenever you have to choose between the two, look for structural differences, such as the lattice. You can also scratch fluorite using amethyst.