For millennia, jade has been believed to be a “living stone.”
It is said that all stones want to be like jade, a gem set apart by its unique texture, depth, and intermixing colors.
Some might say that these features are “flaws,” gemologically called “inclusions.”
But at Mason-Kay Jade, we disagree. We believe that these attributes are part of what makes each piece of jade interesting and unique, not to mention affordable.
When we source jade, we’re choosing pieces that are durable, long-lasting, and fairly priced. Customers may be surprised to know that we often select uniqueness over perfection, even if it means carrying items that are less expensive. It’s because we truly love the jade, and we want you to too.
In this blog article, we’re going to take you deep into the jade stone to see these “inclusions,” these truly unique features that make each jade a one-of-a-kind, up close.
Dark inclusions of mixed types in nephrite jade, photo courtesy of Jewels of the Trade
Green Nephrite Jade 14K Yellow Gold Drop Earring | UPC #401860 MSRP: $1,330.00
But first - what are we looking at?
Both jades are made of tiny crystals (meaning a jade stone is not a single crystal, as in the case of diamond or ruby), but the nature of their crystalline microstructure is different between the two jades.
Jadeite jade has a granular structure, whereas nephrite jade has a fibrous structure.
Jadeite jade structure
An important note: "Jadeite jade" refers to the gemstone seen in jewelry, whereas "jadeite" refers to a single, microscopic crystal that comprises the jadeite jade aggregate. So when discussing jadeite jade as a gemstone, it's appropriate to call it "jadeite jade" or it's more accurate term "fei cui," but it's incomplete to call it just "jadeite" or "jade" without additional qualifiers.
Jadeite jade's structure is considered granular, so the crystals that are compacted together are grain-like, which is best illustrated in the photo of lavender jade rough below.
Nephrite jade structure
Nephrite jade’s structure is considered to be fibrous, so the crystals stack on top of each other like sheets.
They’re directional, and nephrite jade’s strength comes from the crystals being oriented in as many directions as possible. When too many crystals align in the same direction, the space between them allows for easier breakage. Parallel crystal fibers is what leads to chatoyance in nephrite jade, which we’ll be talking about later in this video so stick around to see cats eye jade under the microscope.
In cases where nephrite jade has very, very fine microstructure as is the case with a lot of tighter Wyoming jades and of course the coveted white material from Hetian in Xinjiang, its crystal sizes are so small and so close together that it doesn’t look directional, it is even similar in some ways to jadeite’s granular nature.
Note: This information tends to be more important for carvers to know, but knowing about this can help in distinguishing between jadeite and nephrite.
Example of Granular Microstructure in Jadeite Jade
Rough Burmese lavender jadeite jade featuring jadeite crystal faces, photo courtesy of Jewels of the Trade
Ignore the saw marks in the photo above, because this is rough jade, but the little flashes are actually flat crystal faces where the saw cut through a larger crystal. Some people will call this “salt” or “sugar.”
By nature of being able to see these crystal faces, we can learn about the jade.
For one, it’s probably not super high quality jadeite jade - because the grains aren’t too small to see. And secondly, if we knew this was jade but we didn’t know which jade, we could be pretty confident that it’s jadeite jade based on these crystal faces. And the color, of course.
Rough jadeite jade from Clear Creek, California, USA courtesy of Sonoran Jade. Photo courtesy of Jewels of the Trade. This rough stone shows an example of granular fracture in jadeite jade.
Conchoidal fracture in smoky quartz, photo courtesy of Jewels of the Trade. Conchoidal fracture will never be seen in jadeite jade, so this reference is useful for jade identification.
When a jadeite jade is fractured, you’ll also be able to see its granular structure.
If the fracture is conchoidal, meaning that it looks like the inside of a shell, that’s a dead giveaway that the stone is not jade.
Note that granular fracture certainly isn’t conclusive for identification because other stones can have it too.
What are Inclusions in Jade?
Closeup up Mason-Kay's Guatemalan jade slice earrings, showing vibrant green patterns that may be caused by either chromium or iron concentrations and albite inclusions. Photo courtesy of Jewels of the Trade.
The same earrings featured in the above closeup. 14K Yellow Gold Translucent Green Jadeite Jade Drop Earrings | UPC #396869. MSRP $1,380.00
Answering the question of what are inclusions in jade is quite complicated, so we're going to start from the beginning. Feel free to scroll down if this feels a little dry.
What is Jade?
Jade is a trade term that can refer to jadeite jade and nephrite jade. Jadeite jade is also called fei cui, and nephrite jade may be sold on the market as Hetian jade regardless of origin. At Mason-Kay Jade, we do not use this confusing terminology. We encourage other jade sellers to refer to nephrite jade as "nephrite jade," not "Hetian jade" or "jade" without additional qualifiers.
| Side note: The word jade should not be capitalized unless it is the first word in a sentence, a proper noun (meaning it's the name of a person or place), or a title of a book, piece of media, or work of art. We do not capitalize the "s" in sapphire, nor the "d" in diamond. So there is no reason to capitalize the "j" in jade. Thank you for coming to my TED talk. |
As I mentioned earlier in this article, we don’t call jadeite jade “jadeite."
That’s because “jadeite” is a single crystal, and jadeite jade is the gemstone. Jadeite is a mineral, but jadeite jade is an aggregate.
A gemstone is what it is because of its chemical composition and crystal structure. You can’t call something jadeite jade just because it’s green.
Chemically, jadeite jade is comprised of pyroxene minerals jadeite, omphacite, and kosmochlor, and nephrite jade is comprised of the amphibole minerals actinolite and tremolite.
So when people say “What’s the difference between nephrite and jadeite?” That’s the real answer. They have different chemical composition and crystal structure.
Photo courtesy of Jewels of the Trade
This is not an article on the differences in appearance between jadeite jade and nephrite jade, however, we do have an article on that already if you'd like to learn more: Nephrite Jade vs. Jadeite Jade: What's the Difference?
This is not jadeite jade. The above photo depicts a stone called "Turkish purple jade" or "purple jadeite rock," which is an aggregate with complex intermixing of quartz and jadeite (and cinnabar). This material reads as quartz with even such conventional gemological technology as a refractometer, so it's easily distinguished from "real" jade. Photo courtesy of Jewels of the Trade.
Further Clarification on What Constitutes a Jade Stone
Just because a stone has jadeite in it, that doesn’t make it jadeite jade. The stone has to be primarily comprised of jadeite, omphacite, kosmochlor, or a combination of any of these.
If the stone is half jadeite and half omphacite, we still call it jadeite jade in the American trade, but that’s obviously confusing because jadeite is a mineral. So in the future, the trade hopes to transition to calling pyroxene jades "fei cui," which is internationally the most common term for pyroxene jades, currently called jadeite jade.
A stone isn’t nephrite jade because it has actinolite in it. To be nephrite jade, the actinolite, tremolite, or actinolite-tremolite has to have a microcrystalline structure or a massive microcrystalline structure - so a single crystal of actinolite is not jade.
Earrings from the Mason-Kay Slice Collection. Green Nephrite Jade 14K Yellow Gold Drop Earring | UPC #401860 MSRP: $1,330.00
Definition of Inclusion
It's not appropriate to call inclusions “flaws.” They’re not flaws, and in many gemstones, an inclusion can even make the stone more valuable as in the case of horsetail inclusions in demantoid garnet.
Typically, an inclusion within a gemstone is a crystal, a change in the crystal structure, a fracture, etc. - it’s something that sort of disrupts the crystal’s structure. We usually use the term to refer to single-crystal gemstones such as diamond and ruby, but it can technically refer to polycrystalline gems as well.
Jadeite jade is polycrystalline, meaning a jade stone is not one crystal, it’s many crystals. The same goes for nephrite jade.
So, while the literal definition of "gemstone inclusion" doesn't necessarily apply to jade, it's still the most appropriate term for irregularities seen in the stone.
Inclusions Found in Jadeite Jade
I'm not sure I can list all of the inclusions in jadeite jade, but here is the slide from the JOTT Livestream on this topic, which shows a handful of minerals that can be found in jadeite jade / fei cui.
Inclusions in jadeite jade, photo courtesy of Jewels of the Trade
Inclusions Found in Nephrite Jade
Again. I wouldn't know where to procure a list all of the inclusions in nephrite jade, but here is the slide from the JOTT Livestream on this topic, which shows a handful of minerals that can be found in nephrite jade stones:
Inclusions in nephrite jade, photo courtesy of Jewels of the Trade
Distinguishing Crystal Inclusions from Fracture
That's easy. This is what an internal fracture looks like in nephrite jade:
And this is an external fracture in nephrite jade:
And this is an external fracture in jadeite jade:
Identifying Inclusions in Jade
Most inclusions require gemological testing to determine what they are. In general, we can be pretty confident that white "snowflake" inclusions in Guatemalan jadeite jade are often albite or white jadeite. Nephrite inclusions such as thulite (which is pink) tends to be easily identified, and even magnetite (which is metallic.) Additionally, quartz inclusions in nephrite tend to be easily identified.
Blue-Green Guatemalan Jadeite Jade 14K Yellow Gold Necklace | UPC #403185. MSRP: $1,630.00. Photo courtesy of Jewels of the Trade
But what about the inclusions in the above slice of Guatemalan jade? If we take a closer look (below), we see an unusual cross-hatching pattern, verified to be natural by the American carver who cut this stone.
Blue-Green Guatemalan Jadeite Jade 14K Yellow Gold Necklace | UPC #403185. MSRP: $1,630.00. Photo courtesy of Jewels of the Trade
In most cases, we don't know exactly what the inclusions are. Jade's formation conditions, particularly the time in which it formed, the number of times it metasomatized, and what sort of minerals surrounded it during formation, vary dramatically depending on the source.
Jade is often called "The Inscrutable Gem." We are still constantly uncovering more information about jade's past, it's geology, and how to better understand it. The exact nature of many of jade's inclusions remain a mystery to the end consumer (and even the seller!), only to be determined in a laboratory setting.
With that in mind, here are some more photos of jade under the microscope. I hope you can enjoy the beauty - and the mystery - even without conclusive information on what comprises these unique attributes.
Green Nephrite Jade 14K Yellow Gold Drop Earring | UPC #402607 MSRP: $1,220.00 Photo courtesy of Jewels of the Trade
Black Crystal Inclusions: Are They Always Graphite?
The above photo shows Mason-Kay British Columbia nephrite earrings from the Slice Collection under the microscope. The black inclusions shown here, often seen in Canadian nephrites, are often called "graphite inclusions." This may be the case, they may be graphite. But maybe not. High concentrations of chromium or iron in the nephrite crystals can also produce these black crystal inclusions, so these black crystals might just be extremely dark green nephrite as opposed to an altogether different mineral.
Blue Green Guatemalan Jadeite Jade Drop 14K Yellow Gold Earrings | UPC #402638 MSRP: $1,180. Photo courtesy of Jewels of the Trade
Unique Jade Texture, Without Inclusions
In the macro photo above featuring Guatemalan jadeite jade earrings, the viewer may be confused by the almost "fibrous" texture of these stones. Bear in mind, what you're seeing is, in fact, texture - not microstructure. These earrings, in all likelihood, have no noticeable inclusions and are probably >99.999% either jadeite, omphacite, or a combination of the two. The color patterns you're seeing are not inclusions, but just show where color is more concentrated/saturated in the stone. Even without inclusions, these jade earrings can entrance the viewer.
Natural jade with iron staining, courtesy of Flow and Shatter Designs in the JOTT Discord. Photo courtesy of Jewels of the Trade.
Iron Staining
This probably wouldn't be considered an "inclusion," but secondary iron staining can be characterized by a red/brown color. It's worth noting under the microscope because iron staining can be an indicator (albeit non conclusive) of natural jadeite jade, as iron staining is typically bleached out before most treatment. Mason-Kay Jade is very careful not to source jades that are fractured, dry, or iron-stained like the above photo. However, we do stock a variety of yellow and red jadeite jade, which are gem-quality jades with natural secondary iron staining.
Colorless, white jadeite jade under the microscope. Photo courtesy of Jewels of the Trade.
"Wispy" Texture in Jadeite Jade
I want to come back to this, because I don't want you to leave this article confused about fibrous texture. Nephrite jade's microstructure is fibrous, meaning the crystals are elongated and lay on top of each other like sheets. That is entirely different from the above photo, which depicts white jadeite jade under the microscope. This "wispy" texture is characteristic of jadeite jade, and is not the same as fibrous miscrostructure in nephrite jade.
For comparison, an example of nephrite jade's fibrous structure (in this case, the microstructure is considered "massive" microcrystalline, because it's pretty easy to see, even without a macro lens.)
Fibrous structure in nephrite jade. Photo courtesy of Jewels of the Trade
Fibrous Structure in Nephrite Jade
Please note that most nephrite jade does not look quite like the above photo, but this is a very good example of the "sheetlike" stacking of nephrite crystals. Some carvers even compare nephrite's structure to wood grain. Ideally, nephrite jade found in jewelry will have a tighter microstructure than this so it won't be as noticeable to the naked eye. Truly, it's more pertinent for carvers to know. But interesting nonetheless.
'B Jade' under the microscope. No indication of treatment, necessitating the need for advanced gemological testing. Photo courtesy of Jewels of the Trade.
'B Jade' Under a Microscope
We didn't discuss treated jades much in this article, as many of our articles before this have already delved deeper into that topic. 'B Jade' refers to jade that has been acid-bleached and impregnated with either polymer, wax, or resin. If you are concerned about B Jade, fret not. Not only does Mason-Kay never sell 'B Jade,' we actually test every single piece we stock to guarantee that the pieces we sell are natural, untreated 'A Jade.'
However, testing is not so easy. And most of the time, there is no reliable "at home" test for determining whether jadeite jade is natural. The above photo depicts 'B Jade' under the microscope, showing no indication of treatment. This is problematic because B Jade is more brittle, less valuable, and less stable than natural jadeite jade. Additionally, it's worth very little - and is often sold to customers for unfairly high prices.
That's why it's so important to shop with a seller you trust. If you purchased a piece of jade somewhere else and want to know if it's treated, you can send it to Mason-Kay for jade testing. We also offer valuation services if you need your natural jadeite jade to be appraised.
Learn more about treated jade on the Mason-Kay Blog: Top 3 Reasons to Not Buy Treated Jade
Forget stargazing. One can get lost just looking at jade under the microscope. If you're interested in seeing more jades under the microscope, check out this video from Jewels of the Trade featuring the Mason-Kay Slice Collection:
