Cubic zirconia (sometimes called simply 'cz') is the most popular diamond simulant in the world today. It is an oxide of the metallic element zirconium, ZrO². It has a hardness of about 8.5 on the Mohs hardness scale, as opposed to diamond, which is 10, sapphire/ruby which is 9, topaz which is 8, and so on. The refractive index of CZ is 2.42. It can be made in nearly any color and can be faceted into many cuts.
CZ occurs naturally but in pieces too small for jewelry purposes. It wasn't until the 1970s however when Soviet scientists learned how to grow this mineral in the laboratory, at which time jewelry designers first took notice of cubic zirconia. For the first few years it was on the market it was often sold for as much as $20 per carat (!!) and was only available in a few colors.
CZ is more dense than diamond -- it weighs more for its size than diamond does. Sapphire and ruby, both of which are the same gemstone, just different colors, are also more dense than diamond. CZ is about 75% heavier than diamond. As such, a CZ's size is referred to in carats usually in comparison to diamonds. CZs are more accurately measured in millimeters, referring to the width of the stone. A 6.5 mm cubic zirconia is equal in size to a one-carat diamond and actually weighs about 1.75 carats.
CZ isn't grown/created like any other imitation gemstone in the world, either. A high radio-frequency "skull crucible" system is used, in which the melting zirconia powder actually creates the sides of its own container during its formation. Cooling this extremely hot molten ore becomes the most crucial step in the entire process. A carefully programmed cooling procedure is required to form the flawless crystals -- metal pipes in a coil-shape with water running through them are used to cool down the material, in the center.
CZ occurs naturally but in pieces too small for jewelry purposes. It wasn't until the 1970s however when Soviet scientists learned how to grow this mineral in the laboratory, at which time jewelry designers first took notice of cubic zirconia. For the first few years it was on the market it was often sold for as much as $20 per carat (!!) and was only available in a few colors.
CZ is more dense than diamond -- it weighs more for its size than diamond does. Sapphire and ruby, both of which are the same gemstone, just different colors, are also more dense than diamond. CZ is about 75% heavier than diamond. As such, a CZ's size is referred to in carats usually in comparison to diamonds. CZs are more accurately measured in millimeters, referring to the width of the stone. A 6.5 mm cubic zirconia is equal in size to a one-carat diamond and actually weighs about 1.75 carats.
CZ isn't grown/created like any other imitation gemstone in the world, either. A high radio-frequency "skull crucible" system is used, in which the melting zirconia powder actually creates the sides of its own container during its formation. Cooling this extremely hot molten ore becomes the most crucial step in the entire process. A carefully programmed cooling procedure is required to form the flawless crystals -- metal pipes in a coil-shape with water running through them are used to cool down the material, in the center.
CZ is often spoken of negatively because it is a synthetic gemstone. It is durable, very bright, can be grown in a varity of colors and when well cut it is a very convincing diamond substitute.
See related:
diamond
gold
platinum
bling
bling bling
jewelry
See related:
diamond
gold
platinum
bling
bling bling
jewelry
by Ryan Thompson September 25, 2004
Get the cubic zirconia mug.Zero Interest Rate Policy. A controversial policy pursued by central banks in countries whose economies have collapsed, in an effort to reflate the system. Under ZIRP, a country's central bank sets the interest rate to zero or near zero, to make capital purchases more attractive.
The policy is controversial because it is not clear that it achieves the desired objective, and in fact may lead to a so-called liquidity trap, or a self-reinforcing slow deflation of the economy. Japan has lived with ZIRP since its stock and real estate markets crashed in 1990, and their economy has stagnated ever since. The United States is presently and foolishly following the Japan ZIRP model, with a similar outcome all but assured.
The policy is controversial because it is not clear that it achieves the desired objective, and in fact may lead to a so-called liquidity trap, or a self-reinforcing slow deflation of the economy. Japan has lived with ZIRP since its stock and real estate markets crashed in 1990, and their economy has stagnated ever since. The United States is presently and foolishly following the Japan ZIRP model, with a similar outcome all but assured.
by shlimper44 July 8, 2009
Get the ZIRP mug.A loyal friend. With patience beyond that of what any sane person would have.
A Zirk is a person that will do the right thing at the worst possible moment.
A friend that does not abandon, a friend that does not judge.
A person that will put the needs of a loved one, even before their own.
As with cheese and wine, a Zirk is beyond picky (and snobby) when it comes to choosing a mate/ or life partner.
But if you are lucky enough to be picked by a Zirk, never let him go.
If a Zirk were a color, he would be orange.
Unusual, bright and fascinating at times when you expect it the least.
A Zirk is a person that will do the right thing at the worst possible moment.
A friend that does not abandon, a friend that does not judge.
A person that will put the needs of a loved one, even before their own.
As with cheese and wine, a Zirk is beyond picky (and snobby) when it comes to choosing a mate/ or life partner.
But if you are lucky enough to be picked by a Zirk, never let him go.
If a Zirk were a color, he would be orange.
Unusual, bright and fascinating at times when you expect it the least.
by Dicci February 3, 2021
Get the Zirk mug.Zira is the girl who every girl is jealous of because of her incredible good looks. Every girl wants to be her, and every boy wants to be with her. She is completely gorgeous inside and out. Although a tad loopy and crazy she has the nicest personality and the best sense of humor you can imagine.
by TanglingCharlie November 8, 2010
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Girlfriend: You know - diamonds are a girls best friend.
Boyfriend: yeah? Not a guys. That diamond burned a hole in my wallet. I think I'll stick with dogs and cubic zirconia.
Boyfriend: yeah? Not a guys. That diamond burned a hole in my wallet. I think I'll stick with dogs and cubic zirconia.
by Jbomb11 March 21, 2009
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The person is a complete package of a sexy figure, accompanied by a sexy voice.
The person is a complete package of a sexy figure, accompanied by a sexy voice.
by dyslexiqra September 24, 2011
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