Gem Articles

The word CABOCHON in the gem business is often used wrongly, to the point that some people miss the actual meaning of it especially here in Tanzania. If you are in the gem business make sure you use this word correctly.

The word CABOCHON explains the cutting style of a gemstone not the quality of the gemstone as many think. You will find that some miners and even gem sellers use this word to define the quality of the gemstone.

In the Gem cutting, there are styles which are famous, we will take a look at few of them.

1. Facet

Is a gem cutting style with many sides well cut and polished. The gem has to be transparent in order to cut as a facet. E.g. Diamond, Ruby, Sapphire or any other transparent gem. Below is facet image.

2. Cabochon

Cabochon is a smooth rounded polished gem has a domed top with a flat or curved base. Below are cabochon images. The good example is chalcedony, chrysoprase, coral or opal

Why some gemstones must cut in a Cabochon style?

§ Some gems appear more presentable when cutting them cabochon. There are some stones in order for them to shine the gem cutter must cut the cabochon style, e.g. Moonstone, opal, Star Ruby, Star Sapphire, Sunstone. ruby zoisite, ruby fuchsite,

§ The second reason is when the stone has visible inclusions, so to improve the value of the stone, it must be cut in the 'cabochon’ style.

§ Some of the gemstones are “opaque”, they do not allow the light to penetrate e.g. malachite, agate, coral, ruby zoisite, ruby fuchsite, amazonite, aventurine and feldspar

3. Carving

This is another style of gem cutting, where as a gemstone is cut to design a desired figure or shape. E.g. map figure, car figure, animal figure etc. The good example is ruby zoisite.      

I hope that you have understood the meaning of word “CABOCHON”. Let me remind you once again, it is a cutting style and not the quality of the gemstone.

Not every gemstone, you can sell at a big lump sum amount. There are some gemstones that to make big money, you must sell many kg even tons.

When I say lump sum, I mean US$ 100,000 and above per piece of the gemstone. 

You can’t sell gems such as citrine, red garnet weighing 1 - 10 grams for US$1,000 to US$100,000 per piece. 

Below are some of the gemstones that can command big prices;

1. Diamonds

2. Rubies

3. Sapphires

4. Emeralds

5. Spinals

6. Tsavorite garnets

From the above mentioned gemstones, if you can manage to get piece weighing between 5-10 grams per piece. You are very much assured to make big sales of between US$ 1,000 to US$ 1000,000. But sometimes it may depend on the color.

If you may observe in auctions such as Christie's Auctions, you will discover that it is the same gemstones that I mentioned above that command big prices. 

Here are some examples of big sales at Christie's Auctions;

Ruby Ring

8.26ct

Cushion shaped

Sold at Sotheby for US$ 8.6 million

Sapphire Ring

27.54ct

Step cut

Sold at Sotheby for US$ 5.9 million

Burmese Ruby

29.62ct

Oval cut

Sold at Sotheby for

US$7,338,462.HongKong April 2014

Burmese Ruby

6.04ct

Sold at Christie HongKong for

US$3,331,380 May 2012

Kashmir Sapphire

27.54ct

Step cut

Sold for US$ 5,984,474

We are in the information age, whereby you can buy many thing without any geographical hindrance. There are couple of things you should take note of while buying gemstones online. This will help avoiding of one to be conned.

Buying from b2b (business to business)

It’s good to identify the website you want to buy gemstones from if it is b2b or individual companies. In b2b, some companies or individuals advertize their products and people either visit or shop online. These websites are not concerned with the quality of the products advertised. It is the responsibility of the seller to produce sufficient information of the products. That is to say if you are buying from b2b make sure you are satisfied with the product before buying it. Some of the b2b websites are; “Alibaba” ,”Amazon”, “ebay”.

Individual companies or a person 

These are companies or individuals that you can see b2b websites on the internet. But sometimes reaching them is the bit difficult, and even if you manage to find them the assurance of them is very little. Why? Because you are not sure whether you buying from peson or company.

Understand Gem Terminology

In order to avoid loss while buying the gemstones, it’s good you understand the gem terminologies or the gem language. Such as cabochon cut, opeque , v1v2 , translucent or treated. There are so many gem terminologies or languages, your assignment is to understand the language used on displayed gem before purchasing it especially online, where you can’t ask questions. 

Don’t be carried away by the picture displayed, rather get the details provided. If you do not know the language used, go and find out first the meaning before you buy. One may ask, where can I get such information on gemology? There are so many institutions across the world such as GIA which can provide such information, but you can also visit some website for meaning such as “www.google.com”.

Physical Location

Make sure the company you visit on web has a physical location address in case of anything you can easily follow up. Precaution!do not purchase online from the company you do not sure of whereabouts its location or base. You can find such provide phone number and email address only no physical address attached to it.

Email

Make sure the company you want to deal with provides a company email, because some websites have the contacts without providing their company emails. Be wise do not fall on such traps. The company should put the visible company email for the customers to access easily for both purchase and enquiry.

Phone number

Also the company should provide a phone number, for customers to reach them out for clarifications.

Photos of company or staff

The company should put the picture of either staff team (management), C.E.O, or business owner etc., this is very important for it gives the assurance to customer.

Legal Documents

This is another way of getting legal information of the company from the authority of the legal documents provider. It could be the ministry, revenue authority, licensing authority, gemstone boards etc.

Payment Modes

Know the payment mode used by the company and see if it’s convenient for you before purchasing. For instance not every country use “PayPal”, check the one provided if can help you buy.

Shipping 

Since gemstones are precious, you won’t give the postal address for delivery. Use courier companies to deliver your parcel such as; DHL, EMS, FEDEX, UPS, it is easy to follow up on them. You get to know the movement of your parcel from one point to another.

Return Policy

Get to know if the company has a “return policy”. In some countries the return policy is difficult to implement. For instance here in Tanzania, you have to pay for every gem you export as well as import, even if the gemstone exported is return for one reason or another, you will have to pay for it again. Make terms of agreement when the gemstones sent to you are contrary to what you ordered, on return policy issue.

Advantages of Ordering Gemstones Online

First of all you save transportation money which could be used to go where the gemstones are. Instead the US$1000 that you could have used for air ticket can buy a gemstone instead. 

Likewise the money that could be used to board a hotel during your stay on particular country, can also purchase the gemstone up to a US$500 for a five day hotel pay. 

I therefore recommend you buy online once you know the procedure of buying

online.

Nowadays we have a mix-up concerning the color change gemstones, multicolor gemstones and bicolor gemstones. Especially when handling the rough gemstones.

Characteristics Of Change Color Gemstones

It shows two colors while it does not have two colors.

The second color can be seen while you use an incandescent light.

For instance the gemstone will change from green to red once is put under the incandescent light.

Source Of Light

For you to see the color change on the gemstone you must have two types of light sources. That is “fluorescent light” and “incandescent light”.

Fluorescent light

This one can be obtained by getting fluorescent bulb and even the sunlight can do the work just as good as the fluorescent bulb.

Incandescent light 

This can be obtained by using an incandescent lamp which has incandescent bulb or candle.

How to see the Color Change in Gemstones?

The principals are the same, even if it is a synthetic sapphire. The same principals are applicable for all gemstones. Just take a gemstone that shows the color change, then put it under the fluorescent lamp, take for instance sapphire. To see the second color, take the same gemstone put it under the incandescent lamp.

Then you will see the second color.

By this procedure the sapphire which appeared green under fluorescent light will change to red under incandescent light. And once taken away from the incandescent light, it will return to green again.

Contradiction 

The multicolor gemstones are not the change color gemstones, such as tourmalines is the multicolor and not the change color. Especially sapphire gotten from Tanga region here in Tanzania has more than one color. And this does not make this type of sapphire to be the change color, famously known as “Umba sapphire”. 

The amazing thing is the colors can be seen while under the fluorescent lamp only, this confirms to you that it’s a multicolored sapphire or a bicolored sapphire NOT change color.

Here are some color change gemstones

Sapphires

Spinels

Garnets

Alexandrites

Take note since you are in the gemstone field, it is good you have those two types of torch or lamp. That is fluorescent lamp/torch and incandescent lamp/torch.

A blind purchase is a purchase made without adequate knowledge on the product you are buying. This kind of purchase sometimes can be on the both sides, the buyer and the seller. 

If you are a customer and you want to buy jewelry from a jewelry store, make sure you have enough knowledge on what you want to buy. If you think you are not sure of what you buy, ask the seller about the gem or jewelry you intend to buy, may be a ring, earrings, necklace etc.

It’s good to have enough information on the product, such as in which occasions the item can be worn. Or what kind of chemicals or solutions were used to process the product, to know how to treat while cleansing it. Is it water only used to wash? or is there any special chemical to wash it or cleanse it.

And if you are a jewelry retailer used this opportunity to explain your products to your customers, such as which ring to put on in which occasion or in daily routine.

There is a wrong belief about gemstones, to the point that many people are afraid to do gemstone business or learn about gemstone. We will be looking for some reasons why is it so.

Powers of darkness

Many have connected the gemstone business with the powers of darkness. Many have been forced to believe that for one to do the gemstone business successfully, one must do some rituals to appease some spirits. Some who own mines have been made to believe that, for the mine to produce they must sacrifice to some spirits. And if you take a closer look, you will discover these rituals and sacrifices are not that fundamental. Just follow the principals to get the business done profitably 

If a mine collapse, check if the safety regulatory protocol was followed during the mining process. If you use equipment either of poor quality or less effective, be rest assured the digging will take a long time before you get any minerals, or the tunnel has gone a long distance. 

Also if you dig for a long time without getting anything, it is very possible you have missed the rock targeted. We have discovered that, here in Tanzania foreigners come to do mining business and getting gemstones without even using the powers of darkness (rituals and sacrifices) one thing you will note about these foreign miners is, they come with modern equipment and good experts in the mining industry.

Simply because gemstones are mined from underground, so some people conclude that they are demonic. Let me ask about petroleum products such as diesel or petrol we use in our cars, are they demonic? because they extract petrol under the sea thousands of meters below sea level, yet we use it in our cars unquestionable. Therefore gemstone is just as good as any other product; the best we can do is to learn about it.

Fear of Frauds & Swindling

Many believe that gemstone business is full of Fraud and Swindling, in either selling or buying. Now the issue of Fraud & Swindling is found in many areas of business not in gemstones only, and I can’t deny the fact that it does exist. What is important is that get enough information about the gemstone business, as well as the gemstones products. Not every red stone is a ruby, not every blue stone from Umba is a blue sapphire. It could be a blue scapolite or lolite. 

Get the knowledge of gemstone and the use of proper tools for identification or you can use a professional to help you, they could be a dealers, lab technicians, and gemologists.

Fear of Robbery

Some have been made to believe that once you have the gemstones at home, you can be invaded with armed robbers. These concepts are irrelevant when it comes to business. What you are supposed to do is to take necessary security measures in order to avoid attracting thieves and robbers. And during business transactions just take all the precautions necessary. 

In finishing, I would like to say that the three misconceptions I have mentioned are irrelevant. These gemstones are the same that God created in the times of Adam, they have not changed. Look around you, are there gemstones? go and learn from those who have succeeded in this business, how did they do it to reach where they are today. 

Before we go into the difference let us first look at the definition terms.

Blemish is an irregularity that is confined to the surface of a polished gemstone, while Inclusion is enclosed within the gemstone or reaches the surface from the interior.

In other words inclusion is an irregularity in the gemstone, sometimes within the gemstone or sometimes starting from the surface going to the inner part of the gemstone. Most of the time when gemstone has an inclusion, it is not easy to remove it. If you try to remove it by force you will end up reducing the weight of a gemstone.

And blemish is an irregularity on the surface of a gemstone, which means is easy to remove during gem cutting. 

Some of the blemish occurs during the gem movement. Gemstone blemish can also happen after cutting if there is a poor handling. It is advisable to pack well to avoid scratches which can lead to blemish, so pack well and differently.

But one uniqueness about inclusion is, it can help identify the gemstone if is natural or synthetic.

When it comes to identify gemstones, you must know your motive. Whether a natural or synthetic, neither cut is or rough gemstones sometimes they confuse when it comes to distinction. For instance a blue sapphire looks very much like a tanzanite, or pink spinal looks like pink tourmaline. Like brown zircon and brown citrine. And because of that you need gemstone tools to identify and differentiate them.

It is also advisable

-to do at least three different tests to have the right identification. 

-Also you must have adequate knowledge and know how to use the gemstone tools.

- Absence of proper use of gemstone tools, or not having adequate knowledge on gemstones can lead to wrong results.

Reasons for Gemstones identification

Let us look at the essence of gemstone identification, and what you should know

Is it natural or synthetic?

Is it treated or not?

Is it simulant or not?

What is the type of the particular gemstone?

Things to considering when identification gemstones

Color

Color is one of the properties used in identifying a gemstone. Some of them by looking at their colors you can easily identify them. For example, the colors on the opal gemstones are different from the color on the agate gemstones. Some of the gemstones can be identified by the combinations of their colors. Such as amethyst and citrine becoming ametrine. In other case when we look at the gemstone and discovering that it’s a sapphire red in color, then we call it ruby.

Let us look at another example, how the color can distinguish a gemstone from another. When Beryl is blue in color, we call it “aquamarine”, simply because it is blue in color. When Beryl is yellow in color we call it “heliodor”, if it is green we call it “emerald” but it’s the same Beryl gemstone.

I hope you have seen how helpful the color is in the identification exercise.

Hardness

This is another property in gemstone identification; you can distinguish between one gemstone from another by its hardness. When a blue sapphire is put together with a tanzanite, they look very much alike. But hardness can distinguish them; the hardness of sapphire is 9 while the hardness of tanzanite is around 6 to 7. This can be done by using gemstone testing tools. Please take note, do not use hardness test to distinguish between the natural and the synthetic gem,because both of them have the same hardness.

Refraction Index

What is RI? It is a ratio of light speed in the air to the light speed in a medium. We have a single reflection(SR) and a double reflection(DR). The instrument used here is called Refractometer. Through this instrument you can know whether the stone is SR or DR. even when the gemstone is unknown to you, by using Refractometer you can identify it. Gemstone Refractive Index is like human fingerprint and RI is most useful method in identifying gemstones.

Specific Gravity

This test is also very helpful especially to unknown gemstones, and in this whole exercise there is what is known as “specific gravity testing set” which have normal scale. But the scalemust be “legal for trade scale”. 

For “Gemstone identification”, you either get qualified personnel or go for training on gemstone identification.

Your eye

Your eyes are tool number one in gem identification. Some may not agree with this truth. You can’t identify any gem without using human eyes. Your eyes can bring good result in rough gemstones.

There are other tools you must have them in gemstone identification like

Microscope

Dichroscope

Spectroscopes

Ultra Violet Light Testing Equipment

Polariscope

Fiber Optic Light System

Incandescent light 

Gemstones is a subject just as good as any other subject, such as IT, agriculture etc. And it’s good if you are in gemstone business or you are planning to do gemstone business to know the terminology used in this business. Otherwise you may be a stranger in the gemstone market.

Here, I would like to show you some of the gemstone terminologies frequently used. You will not learn them in one day or one week, it may take few months or years to master them.

Below is a list of some of the gem terminologies, but it is your responsibility to find out their meaning of each.

1) Treatment

2) Treated

3) Heated

4) Blemish

5) Inclusions

6) Stimulant

7) Eye clean

8) Loup clean

9) Phenomenon

10) Synthetic gem

11) Transparent

12) Translucent

13) Opaque

14) Fancy color

15) Fancy cut

16) Melee

17) Cabochon

18) Manmade gemstone

19) Lab created

20) Lab grown