Tuesday, 29 September 2020 12:38

Moissanite


Color: Colorless, Green, Yellow
Hardness: 9.25 Mohs
Specific Gravity: 3.21 - 3.22  
Refractive Index:  2.65 - 2.69 


What is Moissanite?
Moissanite has been getting a lot of attention lately especially among the young people who are planning to get onboard of marriage life and do not want to get diamond. Dr Henri Moissan (yes, this is how the gemstone was named) found a small amount of a new mineral while inspecting a meteorite in Arizona. The mineral is naturally came from the outer space. It was the most brilliant stone he has ever seen, full of luster, fire and hard. But the sample was very little, it wasn't even enough to make a ring with it.

Where Can I Find Moissanite?
It is unlikely you will find moissanite in nature. It is a rare mineral. It has been discovered only in a few rocks and meteorites. But thanks to science, we can get it from jewelry stores who sell moissanites all around the world.

Should I Buy Moissanite?
In short, YES. Moissanite is a gemstone by itself. It is not a diamond replacement just because its appearance is similar to diamond. We love how moissanites are hard enough to resist wear and tear of your daily hits and bumps.

Why Should I Choose Moissanite?
Here are 5 benefits of choosing moissanite:

  1. Low Price. This is the biggest advantage of moissanite. You will be able to find a moissanite engagement ring for much cheaper than of diamond.

  2. Brilliant. Moissanite is much brilliant than diamond. They have a very high refraction and dispersion, more than of diamonds!

  3. Strong and Durable. It is strong enough to last despite taking hits from everyday life over the years. Although moissanites are rank lower than diamonds in terms of hardness, they have proven to withstand the same wears and tears just like diamonds. Be assured that they will stay as clear as new for the rest of your life.

  4. Eco-Friendly and Sustainable. Most moissanites that are commercially available, did not go through mining process. They are made in labs, which is sustainable and do not cause environment problems.

  5. Ethical and Conflict-Free. We've all seen the movie about conflict diamonds in a mineral-rich continent. People are fighting each other to get higher profits from diamond mines. The reality of moissanites are far from this, they are free of conflicts.

 

TIPS for Buying Moissanite to Make Moissanite Engagement Ring 
You may be well aware that moissanites are created in labs. The appearance of moissanite can be mistaken with diamond or even cubic zirconia. Here are some tips you can follow before deciding to buy at your preferred jewelry store. 

  1. Certificate. For your own peace of mind, ask for a certified moissanite which usually come with each stone. High quality moissanites are usually come with certificate, and the serial number is laser-printed on the moissanite itself. Look for it when you make a visit to your jewelry store. 

  2. Get Measured. Make sure you are properly measured to avoid any discomfort. If this is a surprise, try to get your partner's ring size as accurate as possible.

  3. Color. Like diamond, moissanite has color grades. Colorless is the most common color for engagement rings.
  4. Carat. Moissanites are about 7% lighter than diamond. A diamond with 1.00 carat size (diameter 6.5mm) will weigh 1.00 carat, while moissanite with the same diameter (6.5mm) will weigh 0.93 carat. It is common for jeweler to call a 6.5mm moissanite as 1.00 carat moissanite.

 

Published in Gemstones
Wednesday, 11 March 2020 11:18

Green Sapphire


Color: Green (light to dark)
Hardness: 9 Mohs
Specific Gravity: 3.99 - 4.00  
Refractive Index:  1.762 - 1.778 


How Durable is Green Sapphire?
We are talking about the second hardest mineral after diamond, all sapphires belong to corundum family, which rated 9 on the Mohs scale. Cut green sapphires are both hard and tough, make it perfect for daily wear.

Color Variations
The color of green sapphires can vary dramatically in hue, tone, and saturation. We've seen green sapphires in a very light green color, yellowish-green, bluish-green, to an extremely dark and rich color.

Where Are Green Sapphires From?
The mines in Australia also produces green sapphire. Sri Lanka is believed to have the finest ones, but it is very rare. Most of the green sapphire you will see on the market is from Thailand. This is why you can buy green sapphire from Shiraz Jewelry for a very low price.

What To Look For When Making A Green Sapphire Ring?
We've seen an increase in colored stone engagement rings in the past few years (we're now in 2020), especially young couples. Here are few things you have too look at:

  1. Color. This is the most important factor in determining the value and beauty of green sapphire. A deep and intense green color is the most sought after.

  2. Hue. Green sapphires could have hints of yellow or blue, which affects the overall appearance of the stone. From our experience, they could enrich the color, and some customers really love the yellowish or bluish green sapphires. We love them all!

  3. Clarity. Like any other gemstone, clarity is one factor you should consider. Most green sapphires contain long, needle-like lines, called rutile needles. This is common. It is extremely rare to find a green sapphire without these inclusions. A clean, no obvious inclusion green sapphire, is valuable.

  4. Cut. The most common cut for green sapphires are oval, round, and cushion. It is also pretty common to see them in pear, emerald, and princess cut. Whatever the cut is, a green sapphire should have a symmetrical cut that reflects light at the correct angles to display the luster.

  5. Weight. Green sapphire price, like any other gemstones, is measured by carat weight. The price will significantly increased as the carat weight increases.

 

TIPS for Buying Green Sapphire
You may be well aware that there are synthetic sapphires in the gemstone market. Getting what seems to be the best deal ever, may well be a 'too good to be true'. Here are some tips you can follow before deciding to buy. 

  1. See it directly. There is a lot of difference when looking at gemstone online versus directly using your own eyes. This is because when we try to capture the color and beauty of green sapphire, our camera lens may capture it differently.

  2. Ask for gem inspection under natural light. By far, natural sunlight is the best light you can get when seeing gemstone. After all, the sunlight is coming from the same sun you are used to whether you are in Thailand or in Europe (or anywhere else)

  3. Certificate. This piece of paper may contain details of your green sapphire. It is a very useful information, and make sure you keep it well.

 

Published in Gemstones
Tuesday, 02 July 2019 22:13

Rhodolite


Color: Red with brown tint
Hardness: 7 - 7.5 Mohs
Specific Gravity: 3.65 - 3.80  
Refractive Index:  1.730 - 1.760 


What is Rhodolite?
In simple word, Rhodolite is rose-colored garnet. Rhodolite is a name for red with brown tint mineral pyrope, family of garnet group. They appear as transparent red-pink-purplish gemstones, including all the different color between violet and red. The color, combined with their brilliance, durability (7 to 7.5 Mohs is considered hard enough for jewelry that can be worn everyday), and availability of Rhodolites have brought some strong demand for the gem in the jewelry industry.

Where are Rhodolites coming from?
Most deposits are from Sri Lanka, Brazil, Tanzania, Madagascar, etc.

How much is a Rhodolite?
You'd probably already know that the bigger the carat, the more expensive a stone will be. Also the better the quality (ie: no inclusion, good cutting, great luster) the higher the price per carat. Luckily, Rhodolite is abundant, and the price of Rhodolite can go as low as US$26 per carat or about 800 Baht per carat. Considering the quality, experts expected the price to be appreciated much higher rapidly.

Why are Rhodolite so popular?
Simply because of the color and hardness. They allow you to have a particular look without using rubies, which are extremely much expensive. So next time you visit local jewelry store, ask for Rhodolite if you don't want to spend much. You may find interesting piece that suits your need.

 

Published in Gemstones
Monday, 01 July 2019 15:22

Rubellite


Color: Pink, red, violet
Hardness: 7 - 7.5 Mohs
Specific Gravity: -  
Refractive Index: 


Rubellite is in fact tourmaline in red or pink color. Classified as 'semi-precious', rubellite is the most valuable tourmaline although green tourmaline is the most desirable color.

Understanding the Price
As you can guess, the price highly depends on size and quality. The bigger the size, the more expensive it is per carat. That goes with the quality too - the cleaner, the more expensive it gets. Luckily, there are large quantities available in the market. Check your nearest jewelry shop for a better price range.

Where are they coming from?
Some Brazilian crystals can reach enormous size but may not be gem quality. Fine ones are from several African countries. Sri Lanka may be the first source of this gem.

 

Published in Gemstones
Thursday, 04 April 2019 16:49

Peridot


Color: Yellow-green, olive green, brownish
Hardness: 6.5 - 7 Mohs
Specific Gravity: 3.27 - 3.37 
Refractive Index:  1.654 - 1.690


It was the early crusaders who brought peridots into Europe during the Middle Ages, and they were very popular. Peridots have been mined for 3,500 years! Now, peridots are everywhere and they are not expensive.

The August birthstone, peridot, has yellow-green or olive green. It was added not long ago in 2016 as the August birthstone along with Sardonyx, and Spinel. Peridot symbolizes strength.

Peridot is a relatively soft stone, ranging from 6.5 to 7 on the hardness scale, making it softer than amethyst or emerald. The stone is also highly sensitive to rapid temperature changes. Because of these, we usually recommend peridot in jewelries that are not for daily use.

Where do Peridots come from ?
Beside from earth, peridots are also come from outer space. A meteorite landed in Siberia back in 1749 with peridot crystals large enough to be set into jewelry. Those mined from earth comes from China, Pakistan, and the United States.

How to clean Peridot jewelry ?
The safest way to clean your peridot jewelry is with warm, soapy water. Do not expose your peridot to drastic temperature changes, which can damage the stone. You should also avoid cleaning peridot in ultrasonic or steam cleaners.

Published in Gemstones
Tuesday, 12 March 2019 13:53

Tanzanite


Color: Sapphire blue, amethyst, violet
Hardness: 6.5 - 7 Mohs
Specific Gravity: 3.35 
Refractive Index:  1.691 - 1.700


The name Tanzanite was introduced by the New York jewelers Tiffany & Co after an East African state called Tanzania. The name is accepted by the gems trade, but scientist refer to it as Blue Zoisite. We have to thank Tiffany & Co for disliking the name 'Blue Zoisite' which sounds pretty much like 'Blue Suicide'.

Where do we get Tanzanite gems
Obviously in Tanzania we can see the mines operating to get tanzanite gems. Nowhere else. However, the government of Tanzania banned the export of rough stones weighing more than one gram. Most likely you will see the fine, polished tanzanite gems when you visit your local gems store.

Heat treatment
Most (if not all) tanzanites used in jewelry industry are heat treated. The temperature is usually between 730-390°C for 30 minutes, and the stones should not have any cracks or bubbles, as they could shatter or the cracks/bubble could increase in size during furnace heating. (Ref: Wikipedia)

Other treatment
Recently, coated tanzanites were discovered and tested by the AGTA and AGL laboratories. A thin layer containing cobalt had been applied to improve the color. It was noted that "coatings in particular are not considered permanent", and in the United States are required to be disclosed at the point of sale.

 

Published in Gemstones
Monday, 11 March 2019 23:47

Topaz


Color: Colorless, yellow, red-brown, light blue, pinky red, pale green
Hardness: 8 Mohs
Specific Gravity: 3.35 - 3.56
Refractive Index:  1.610 - 1.638


In the past all yellow and brown gemstones were called "topaz". With advancement of technology we can happily distinct topaz from the less valuable gemstones such as citrine. A variety of impurities and treatments may make topaz wine red, pale gray, reddish-orange, pale green, or pink (rare), and opaque to transparent.

Important Topaz deposits in the world
Today's most important mines are located in Brazil, Sri Lanka, Burma, and Russia. Some clear topaz crystals from Brazil can reach boulder size and weight hundreds of pounds.

Most desirable Topaz color is pink and orange
Colored topaz are rarely vivid. The most common color is yellow with a red tint. The most valuable is pink. Orange topaz also known as precious topaz. Some topaz can fade on exposure to sunlight.

Topaz must be carefully handled
Although topaz is very hard, they must must be treated with greater care than some other gemstone of similar hardness (such as sapphire, ruby) because of a weakness of atomic bonding in different planes. This gives topaz a tendency to fracture along such a plane if struck with sufficient force. An experienced stone setting would have a good knowledge on how to set topaz into jewelry.

 

Published in Gemstones
Thursday, 28 February 2019 23:07

Sapphire


Color: Blue, colorless, pink, orange, yellow, green, purple, black
Hardness: 9 Mohs
Specific Gravity: 3.99 - 4.00
Refractive Index:  1.766 - 1.774


Sapphire is a precious gemstone which is typically blue, but natural 'fancy' sapphires also occur in yellow, purple, orange, and green colors. They occur also in gray and black, and can be colorless.

Sapphires are hard stone at 9 Mohs, making them perfectly suitable for rings, engagement rings, earrings, pendants, or any other jewelries used everyday.

 

If you can see the tiny lines in this sapphire means the stone is natural and real. Some will dislike it considering...

Posted by Shiraz Jewelry on Sunday, March 31, 2019

 

Heat Treatment
It is common practice to heat natural sapphire to improve or enhance color. Evidences shown that the practice goes back at least to Roman times. Now, heat treatment often accompanied by beryllium under very high heat (just below the melting point of sapphire).

Synthetic Sapphire
Be aware when you found a sapphire gemstone that is very, very, cheap. The saying, 'if it is too good to be true, then probably it is not true" applies here. They are typically very clean without any inclusions. Visit only your trusted store to ensure you get genuine sapphire. 

Published in Gemstones
Thursday, 28 February 2019 22:52

Spinel


Color: Red, pink, violet, yellow, orange, blue, dark green, black
Hardness: 8 Mohs
Specific Gravity: 3.58 - 3.61
Refractive Index:  1.712 - 1.736


Spinel is a fascinating gem that occurs in a wide range of colors, such as carmine-red, blood-red (or 'ruby-spinel'), brownish-red, rose-red, orange, blue, violet-blue, dark blue, purple, greenish, and black. 

Large fine spinels are great treasures, yet few people know of their existence. That is because spinel sometimes associated with ruby and sapphire. The hardness of 8 on the Mohs scale makes spinels durable gems, suitable for daily wear jewelry.

Where are spinels coming from?
Main deposits in Burma (Myanmar) and in Sri Lanka. There are deposits in Thailand too, although not too large. 

Should you be worried of synthetic spinels when buying natural spinel?
Yes. Synthetic spinels are commonly seen in class rings and inexpensive birthstone jewelry. Synthetic spinels have been on the market since 1920s. They imitate natural spinel, and also many other gems. 

But since natural spinels are very hard, lovely, and durable, spinels should be more popular that they are now - the current neglect is due to a lack of exposure to the public by the jewelry trade. This is your chance  to get a real, natural spinel when you visit Chiang Mai, at a price that is a bargain.

Some spinel gemstone from Shiraz Jewelry in Chiang Mai.

Published in Gemstones
Thursday, 28 February 2019 01:04

Emerald


Color: Light green, yellow green, dark green
Hardness: 7.5 - 8 Mohs
Specific Gravity: 2.67 - 2.78
Refractive Index:  1.576 - 1.582


Emerald derived its name from Smaragdos which means 'green stone'.Its green is incomparable, and is therefore called 'emerald green'.

Only the finest qualities are transparent. Often clouded by inclusions (liquid or gas bubbles, cracks, and crystals). These are not necessarily classified as faults, but are evidences as to the genuineness of the stone as compared with synthetic and other imitations. Because most emeralds are highly included, their toughness (resistance to breakage) is classified as generally poor.

Treatments
Most emeralds are oiled in order to fill in cracks so that clarity and stability are improved. The use of oil is traditional and largely accepted by the gem trade.

Published in Gemstones
Page 1 of 2