Xiong Yang

NATURAL OPAL / SYNTHETIC OPAL.
FLUORESCENCE / PHOSPHORESCENCE.

In response to previous post of a pendant fitted with 21 synthetic opals. A question has come up whether I could possibly take photos of the fluorescence of natural and synthetic opal.
IF it is in my capabilities I am always willing to show something of what I know by experience. But I am not an expert in opal. Nevertheless, I wish to make an attempt with what I have in my possession. And that, of course, is not as much as a full-fledged lab. And yet I am happy to show some! Of course it is always better if you have the stones in front of you, can hold them and experiment yourself. But FB still gives the chance to show some.

The following picture shows 28 stones. Superficially, I could label them all as opals. "White" opal, "black" opal. I could label some as hyalite, or opalite. Experts may also be able to connect some with certain deposits. I can't tell you from which location the stone came. Originally purchased, or received as a memento for a work I accomplished to add to my collection of didactic materials. This allowed me to pass on my knowledge to students.

Gathering knowledge has become much easier now than it was 40 to 50 years ago. A lot has changed in the meantime because of better instruments and more extensive possibilities for research. Some things have become obsolete, but that does not mean that what I know is worthless! As a basic knowledge, it is still very useful! So I invite experts to make any improvements to what is posted here. And please do so in a friendly manner. The intent is to help people in a very vast, costly and difficult subject matter that gemmology is. Maybe with my posts I will make people want to go further and enroll in schools of gemology. I am not a competitor, am happy if I can teach someone something here and there by showing. Because my specialty is working with the eyes: learning to perceive. Hope you like this work.

REAL OR FAKE?
I know that some things are no longer allowed to be sold. That does not mean that it no longer exists! I do wish to show these items for DIDACTIC REASONS. How else can one learn the difference between one material and another? I hope that the administrators understand this. I also sell nothing, wish only to pass my knowledge through photographic material. With regards.

On various pages of groups, pictures are posted with stones, or jewelry fitted with stones, with then the question of what it is. BUT these pictures are often so blurred that it is impossible to give a serious answer. Even with sharp pictures one must assume that the answer is always to be taken with a certain reserve. Seeing something on a photo and really having it in your own hands is different! If one has a fully equipped lab, the task is easier, but if you only have a decent magnifierX10, some knowlegde and experience, and some necessary instruments, it is not obvious!
I own no business, but still wish to maintain my expertise of yesteryear: working with a magnifierX10. Now and then I get the chance to examine jewels with gemstones in and find out with the highly necessary instruments, what I have in my hand. I don't own a microscope, but I do know how to work with my magnifying glass, good lighting, a camera and a PC program to magnify what I get to see so I can make some sense to those interested in such a post.
We must at least have knowledge of the various gemstones, their optical and physical properties. A magnifying glass, polariscope, refractometer, Schelsea filter, spectroscope, luminescence source and possibly the heavy liquids is the minimum.
All this is “easy” when you work with loose stones, but it becomes a lot more difficult when the gems are in a jewel!
What can jewels tell us? Are they precious or not? Do they possess Natural, Synthetic gemstones, Glass imitations or otherwise?
For this post I have split the jewelry into 3 groups.
1. In which there are light blue colored cut stones. The question is what stone is it?
The most well known and used stones of that color are Aquamarine, Topaz, Tourmaline, Zircon and Fluorite for natural stones. Synthetic spinel or glass imitation.

2. In which there is a pearl. The question is: a nature/cultivated pearl, or an imitation pearl?

3. One which is rather exceptional.

I hope this post can contribute something.

Those in possession of a fully equipped lab with all possible instruments to view and identify gemstones have it easier than someone who does not possess all that.
I am thinking especially of all those who are just starting out and want to become gemologists. You can get a good theoretical knowledge from solid books, websites, webinars.
But there is also the practical side that needs to be mastered and that is a lot harder! So what does one start with?
By looking at a gemstone with a magnifying glassX10. Because that is the 1st tool that is affordable for everyone and that you can take with you everywhere. With that magnifying glass you can distinguish much more than at first thought.

1. Before beginning a magnifying glass examination, the object must also be cleaned. So just holding a gemstone between 2 fingers is not the right way. For that, tweezers are ideal.

2. One should also have a good exposure. In a semi-dark environment one can't observe much. Sunlight is also not ideal because it affects the proper color of the stone. That also implies that the environment in which you examine the stone should be quite neutral. Gemstones are very often transparent through which you can perceive the environment. Stones are cut cabochon or with facets and these can very easily reflect the color of the environment. If you are wearing something heavily red, it can affect the color of the stone.

3. What can we study with a magnifying glass?

A. How is the stone cut? What shape of cut does it have? Are the facet ribs sharp or rather rounded. Are there any grinding lines visible or not?
B. What type of luster does the stone have? Glass sheen, diamond sheen, waxy, matte, metallic?
C. Is the gemstone damaged? What type of damaged is it? Is the fracture surface smooth, shell-shaped, spongy, rough, granular?
D. Is the color of the stone evenly or irregularly distributed. Are there color bands visible that indicate a certain type of crystal system? Is the color of the stone natural or not? Is it tinted?
E. What we also can determine with a magnifying glass is the stone isotropic or anisotropic? This can be seen by the dichroism phenomenon and if the stone is very double fractured, observing the doubling of the underlying facet ribs.
F. Is there a typical optical effect present? For example, asterism, opalescence, aventurization, etc.
G. Is the stone loupe clean or are there inclusions? If inclusions are present, what type? Gaseous, crystalline, liquid, combination of the different types?

As you can see, you can observe very much with the magnifier
Following all of the above, one can determine whether a stone is natural or synthetic or simply an imitation. I am talking about the "normally" found gemstones in jewelry. Because each in itself has typical properties or characteristics.
Do not speak of certain synthetic stones which are rather rare and can only be recognized through a Raman microscope and certainly not immediately with a magnifyingX10.
Also mentioning that learning to distinguish ALL the different types of stones takes years of practice. New minerals are still being found. Some of which are sometimes suitable for cuting gemstones.

Well, following this introduction I am attaching here some pictures of a very common inclusion in a very common gemstone. I would like to know to which crystal system the stone belongs in which this inclusion is found?
Know that I used different types of light and also held the stone in all possible directions to offer the most accurate images possible.

Dear gem connoisseurs, - owners, - lovers.
I am very honored by the numerous friend requests I receive from you. Excuse me for not responding. I don't want to appear rude or feel too good for it. But I would have to sit at the PC full time reading many posts that you have to get all over the world, if I want to have some idea who I am “friends” with.
Via chat I already regularly receive questions, sometimes appropriate, sometimes inappropriate or barely legible due to awful English. Sorry but mine is already not good to understand everything.
Because I know something about stones, that does not automatically mean that I will buy stones! Know that I will never buy any stones via FB or internet. In this stone world I must not tell you how easily people can be deceived. Do I mean by this that everyone is a cheater? NO, but I don't want to experience that. I would like to share what I know about stones for anyone who wants it: openly on the various interesting groups, where I also get to see exceptional stones, ore where good information is posted.
You are always welcome to comment on my posts.
With regards.
PS: I am a lady and no sir..... 🙂