Important:  This is our old site *archive* and is no longer live (prices and inventory are outdated and not valid). 
Please visit https://betterthandiamond.com directly to view our new site with live shopping.

  Infinite Menus, Copyright 2006, OpenCube Inc. All Rights Reserved.

McAfee Secure sites help keep you safe from identity theft, credit card fraud, spyware, spam, viruses and online scams


Ready to ship jewelry
Earrings
Asha® Diamond Simulant
Takara Cultured 
Diamonds
Natural Diamonds
Cultured Colombian 
Emeralds
Cultured Rubies 
Rings
Prongs
Necklace & Pendants

Care Products

Weekly Special

Amara™ Shell Pearls
Necklace
Earrings

Retail Stores




Questions?
Please contact us via email


Home > Education > Asha® Article
Asha® Scientific Article

Scientific and factual, but biased towards our Asha® version3 cz-based
simulant.


Notes: this article is a work in progress, and as such may at times be in need
of correction, modification or clarification. 
If you have additional commentary or corrections, please email us!


[this article may not be reprinted, and is copyright BetterThanDiamond.com,
2001]


Achieving the diamond-look via man-made gems

If you want to look like a diamond, then your crystal has to handle light in
approximately the same way that diamond does.

Diamond's crystal structure is cubic, specifically "face-centered-cubic".
Common logic would indicate that if you want your crystal to replicate the
optics of a cubic crystal, your crystal should be cubic as well. CZ-based
simulants such as Asha® are thus cubic, specifically "face-centered cubic"
as well. Moissanite, in contrast, has a hexagonal crystal structure. 

The signature optical characteristic of a cubic crystal is that the velocity of
light is constant as it passes through the gem regardless of which way the
light enters. Gems that handle light in such a democratic fashion are termed
"singly refractive", meaning they let light through at a constant speed. Other
crystal structures will let light pass through at one speed if they enter from
certain directions, and slow it down more if it enters from other directions.
This is termed "doubly-refractive", or two different light velocities.

An analogy may help you remember it better: imagine a crystal structure as
a town. If the town sets it so that the speed limit for all roads in the town
is 55mph, then regardless of which road you entered the town on, you could
pass through the town the entire way at 55mph. This would be a single-
speed limit town, or a singly refractive gem. 

Now take another town - this town sets the speed limit at 55mph for certain
roads, but other roads it forces you to only travel at 25mph. Thus,
depending on which exit you took to enter into the town, you might be
traveling through the town at 25mph or 55mph. This would be analogous to a
"doubly-refractive" gem. The net result of such a system would be that some
light would pass through quickly at 55mph, and other light would only pass
through at 25mph. Scientist measure the difference using "birefringence" or
the difference in speed between the highest speed limit and lowest speed
limit in the town. 

Because light cannot pass through a 'doubly-refractive' gem at the same
speed, it tends to give it a "fuzzy" or "blurry" appearance to the eye.
Moissanite of course is doubly-refractive, and it is one optical characteristic
that makes its appearance different than diamond.

Hardness + Toughness = How long your gem will last, or durability.

While many people often look to the Mohs hardness scale in an effort to
make a rough estimation of how long a diamond simulant will last, this is
actually only part of the picture. The Mohs scale is a scale of relative
resistance to scratching, with the emphasis on relative. Diamond is the top
pillar on the Mohs scale, set at 10. Talc is at the bottom, set at 1.
Depending on who can scratch who, other gemstones take their relative
order in this system. (note: The Mohs hardness scale is very imprecise and
in some ways misleading, and usally results in approximations rather than
specific measurements - however, it is the best known scale to the
average person). 

However, while diamond is virtually impervious to scratching, it can be
broken with a hard blow (as many diamond owners have discovered upon
finding chips on the girdle of their gem). On the flip side, Jade can be
easily scratched, yet is one of the toughest materials known. The difference
is Jade has an interlocking crystal network.  Thus, hardness can also result
in brittleness, just as softness can also enhance resistance to breakage/
fracturing. 

1 2 3 4

Asha® is our registered mark 
Content and images, copyright 2007, BetterThanDiamond.com