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Journey to the stone - Star, Cat's Eye, Moonstone

Journey to the stone podcast with Don Kogen about Star, Cat's eye and moonstone


Today in Journey to the Stone, I take you into the world of chatoyancy, of asterism. These are big words for people who are new to the gemstone world, but they're actually very, very simple to understand. They are a rare occurrence that Mother Nature puts into some of the most important gemstones in the world. They are very difficult to find in good quality, and they are very uncommon.

Let's take Ruby, for example. Mogok Ruby currently holds the world record for the highest price of any colored stone in the world: over $1,000,000 a carat. With Emerald coming in four times less at $250,000 a carat; Kashmir Sapphires at $250,000 a carat; even D Flawless Diamonds tap out at around $250,000 to $300,000 a carat, except for Pink Diamonds and Blue Diamonds, which go above $1,000,000 a carat. But the king of all colored gemstones is Ruby.

Very rarely—if you're looking only at the best quality—you will find a clean, crystallized Mogok Ruby that has the presence of a perfect six ray star. Now, as a cutter, you have to know how to cut it to bring out that star. But it is a naturally occurring phenomenon within the crystal structure called asterism. This is created by Rutile needles running through the crystal, and it's the reflection of light off of these Rutile needles that are in the crystal of this particular Ruby dispersing out asterism, which creates that perfect six ray phenomenon. Now there are Stars that are missing a leg, and there are only five rays or four rays; that's of lower grade. And there's a lot of Stars in the world that are completely sleepy or opaque. That is a whole nother thing.

What I am talking about is the rarest Star Rubies in the world, and they can go for high five digits per carat. The colors there—they glow, they're vibrant, but they have a perfect six ray star. That is, by far, the most in-demand Star variety of Ruby in the world. Now, you also get the finest quality Stars, I would say, coming in secondary after the Mogok Mine. Very, very close is the Luc Yen deposit, because of the same geological structure: you've got that marble host rock, you've got that same color. To be honest with you, a lot of labs—actually, primarily most labs—certify Luc Yen, Vietnam, material as Mogok, Burma. They look identical. It's very easy to confuse them, especially if the clarities are good. But the asterism is the same.

Star Ruby ring


The six ray will blow your head off. It is amazing and it glows. There’s nothing more cool than looking at a Star, you know, moving back and forth. And they move naturally, right? They move. And then the crystal of the stone, you can see the glow of the Pigeon Blood Red within the crystal structure. Right. Extremely beautiful and very, very uncommon, especially in the finer grades. I'm always looking for this material. In history, I have given Kat Florence six stones out of my personal collection, and they sold immediately.

Also very difficult to find, and very uncommon, is the Star Sapphire from Burma. If you're looking for a Star Sapphire from Burma, it is very uncommon to find it clean. They're always sleepy. They're always a little bit more included, they’re never perfectly crystallized. I would actually rank the Ruby as a better buy coming out of the Burmese Star. I just can't seem to find it clean. I buy hundreds and hundreds of kilos of rough, and I pull out anything that has the Star or that phenomenon. Just can't get it clean. So really, I end up selling it off. I do cut them. I'll end up selling them off into the market. You'll see very few Burmese Star Sapphires go onto Kat Florence because they don't get the top level of crystallization that is demanded by her royalty, Miss Florence, who demands only, only, only the best.

But in Sri Lanka, you do get some amazing Blue Star Sapphires. I'll tell you my finest quality Blue Star Sapphires, by a long shot, have come out of Sri Lanka, out of the rivers of Ratnapura. Very, very sporadic. And you've got to be smart to be able to see the Star within the crystal structure. They've got a lot of different types that appear. Once again, not common to be perfectly clean. I have collected about ten stones throughout my career. I move hundreds and hundreds of kilos of Sri Lankan rough on a monthly basis and I've only ever got like ten stones that matter. You know, a 5.00 carat, perfectly clean, top cornflower or royal blue Ceylon Sapphire, with a perfect six ray star, is a collectible. You're talking about one in a quarter million, half a million pieces of rough material that pass through my hands that you'll actually find a Star, period. But to get it perfectly clean with the perfect six ray star is extremely rare and very, very uncommon.

What's also cool about Sri Lanka is you do get some pinks, you get some pink colors, which is really nice as well. They don't get the pure red like Mogok or Vietnam. You know—I'll be frank with you—there are Star Rubies out there that come from Sri Lanka. They're not as good as Burma, period. But then if you look at Rubies that come from Ceylon, they're not as good as Burma either, right? It's just the nature of the Chromium concentration within the crystal structure of the material coming out of Luc Yen, Vietnam, the Vietnamese Stone Tract and the Mogok Stone Tract, that are just superior in color.

But they do produce some amazing pinks. You occasionally get some other colors: you get whites, you get the light-colored blues. I'm only talking about the top spectrum of the collectability chain and the stuff that Kat Florence uses. So royal blues, you know, cornflower blues, perfect six ray star, great clarity. Top of the line. Uncommon. Ceylon reigns supreme in the blue. Knock-out. Boom. Red, go Burma. Vietnam, Ceylon, go blue. Those are the top of the line when you're talking about the Star Sapphires of the world.

There are other deposits in the world, like in Madagascar, Tanzania, etc. But those particular deposits don't have the crystallization. They've got amazing Stars, right? There's a lot of Vietnamese Star Rubies, but they're not clean. But the ones that are clean are the money. The money! That's the stuff that is only going to go up in value, because there is a very limited amount of it in the world, 100% natural, not treated and fine colors. That's what you're looking for when you're looking at Stars.

Now, let me take you to the world of Chrysoberyls. Because we've got Milk and Honey Chrysoberyl; it comes out of Sri Lanka as well. This particular material has this yellow effect, and this golden honey effect on the other side. And the eye is perfect. This is called chatoyancy. And see, asterism is the Star, and chatoyancy is what you’ll find in Chrysoberyl. Now, what is Chrysoberyl? Chrysoberyl is a mineral that is also an Alexandrite. The green variety of Chrysoberyl is the green variety Alexandrite. And there is also Alexandrite Cat’s Eye. And let me give you a breakdown, because that is the king of the Cat’s Eye, is the Alexandrite Cat’s Eye. But don't think Chrysoberyl unlike its counterpart.

Milk and Honey Cat's eye ring

So if you take Alexandrite, it has a huge premium over yellow Chrysoberyl. But in Cat's Eye, that changes a little bit. Yellow Cat’s Eye demands huge prices. Huge prices. There is such a collectible, in-demand market for Yellow Chrysoberyl Cat’s Eye, and a perfect eye, if the eye opens and closes as well. So what you do is you take the eye and you twist it to the right, twist it to the left. You must have a direct light source above. So either, you know, some LED light or whatever, move it back and forth and the eye will actually open and close. Gemological phenomenon found in Sri Lanka. These are known as the best Cat’s Eye in the world. The Sri Lankans reign supreme in the Cat's Eye. On the other hand, they also produce some amazing Alexandrites.

But they've got nothing on the Indian Alexandrite Cat’s Eye. The Indian Alexandrite Cat’s Eye is a better color than the Sri Lankan Alexandrite Cat’s Eye. The Sri Lankan Alexander Cat’s Eye: it's got the crystal, but it doesn't have the color. So if you look at a Cat’s Eye, and I've had only one or two in my life, that come out of Russia—because Russia, the mines have been closed for over 100 years. But the predominant amount of Alexandrite Cat’s Eye in the world today came out of the deposit of India, in the Southeast on the Indian continent. And that deposit produced a lot of faceted stones, as well as the biggest array of Cat’s Eye Alexandrite ever.

That mine has been closed for over a decade now. So you can forget about this type of material. And prices have soared exponentially. I mean, they've gone into like five digits per carat for good ones and you just don't see them around. But if you can get an Alexandrite Cat’s Eye from the Indian deposit, it has the best neon green with a 100% change to purple. The key is: can you get it clean?

The Ceylon you'll find clean, but you won't get it perfectly green. It'll be perfectly brown, it'll be brownish green, but it won't have the green, green, green. Brazilian material: you don't really see the Cat’s Eye coming out of Brazil. They do get some Chrysoberyl coming out of Brazil. We do get a lot of amazing Alexandrite coming out of Brazil, but we don't see the chatoyancy effect coming out of there.

Now we're going to take you over to the king of Moonstones. Okay, so you got your Moonstones. Feldspar is the main mineral of Moonstone. So we got Feldspar, and you got some expensive varieties of Feldspar, like Sunstone, coming out of Oregon. Can get up there to four or four and a half, five digits, per carat, for very, very fine grades up in the Oregon Sunstone deposit. Especially if it's something spectacular—50.00 carat, clean, nice Schiller, perfectly red. But they don't really have the Moonstone effect. They have more of a Schiller effect. I'm not going to get into that in this episode. I'm talking about more, you know, the phenomenons.

Moonstone earrings

Now let's talk about the Northern Lights. Let's talk Borealis. Let's talk the colors of the Northern Lights. What you see up at the North Pole, baby! That predominantly comes out of material that is found in Sri Lanka. Now, I'm a big buyer of this rough Ceylon Blue Moonstone. There's two types: Ceylon Blue Moonstone and Ceylon Rainbow Moonstone. I'm a buyer of all this rough material, and I am probably one of the largest exporters of it—all over the world when it comes to this material. But most of it is used in medium grade jewelry. Because it's never clean. It's never clean. You can sell like, okay, I'll get 100 kilos and maybe get less than one gram of crystallized material. So it is so uncommon to see crystallized. It is just unheard of. You can just basically forget about it because there's no way to get it. That is, it's harder for me to find that than it is to find a lot of important other varieties of gems. It's just so rare. It's so rare.

So I've given—I've made it my life's job to cherry pick out. So I'll buy, let's say, 400 kilos of rough and I'll go through it and I'll have my sorters pull it out, and I'll end up with one stone that can cut a 2.00 carat or a 3.00 carat. They're just so rare and so uncommon. And what you're looking for in the Ceylon material, the Rainbow Moonstone or the Blue Moonstone, is clarity. If you can get any specification of clarity, you're in the money.

This stuff can go for big money in Japan. Japanese love it. They love that sheen. It is rare. And if you can get a 3.00 carat, that's unheard of. A 5.00 carat, knock your head off. A 10.00 carat, forget it! There are less than ten in the world that are perfectly clean, and that is what I collect and give to Kat Florence as well.

So you will see the occasional Blue Moonstone, or Rainbow Moonstone, coming from Sri Lanka, in the Kat collection. Please don't get used to that material. Once my collection subsides, we're done forever. I mean, I've been collecting this gem for 20-odd, 30 years, and I've given her all my collection. I'm almost done. So there's not a lot of those stones in the world.

But anyway, I hope you've enjoyed this education on asterism, chatoyancy, and then the Northern Lights. Borealis Aurelius. The lights of them all! Of the Moonstone.

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