Diamond's Structural Secrets Revealed

Jewelry Discussion
1

Good Morning all,

I subscribe to livescience.com and today found a very interesting
article about the unique crystal structure of Diamonds.
Hugs,
Terrie

Diamond’s Structural Secrets Revealed
By Andrea Thompson

Sure, diamonds are shiny and sparkly, but their beauty may
ultimately come from their unique crystal structure, one
mathematician says.

Toshikazu Sunada, of Japan’s Meiji University, conducted a
mathematical analysis of the crystal structure of diamond and
found that it has certain special properties, especially in its
symmetry.

In a crystal, atoms are packed in ordered, repeating patterns,
with the bonds between them holding them tightly together.
Crystals can be represented in models by points (representing
the atoms) connected by lines, or edges in particular patterns.

Two main patterns emerge in crystals: the pattern of edges
connecting the points (or of the bonds between atoms) and the
pattern of a network of connected edges and vertices that
repeats throughout the crystal.

Diamonds have two key properties that distinguish them from
other crystals. One is called "maximal symmetry"while other
crystals can be deformed in models to make them more symmetric,
diamond cannot.

Diamond also has a property similar to circles and spheres,
which look the same no matter which way you rotate them.
Similarly, a diamond crystal looks the same when viewed from the
direction of any edge.

Sunada discovered that out of an infinite universe of
mathematical crystals, only one other shares these two
properties with diamond, a theoretical model Sunada calls the
“K_4 crystal.”

“The K_4 crystal looks no less beautiful than the diamond
crystal,” Sunada said, adding that though it is only theoretical
now, it could one day be found in nature or created.

2

Hi Terrie,

Methinks Mr. Sunada would benefit from a course in crystallography.

The type of symmetry and ordered packing displayed by diamond is not
peculiar to diamond at all, and is shared by a few other minerals.
To be fair, Mr. Sunada appears to be a mathematician, not a
mineralogist or crystallographer, but…

Diamond also has a property similar to circles and spheres, which
look the same no matter which way you rotate them. Similarly, a
diamond crystal looks the same when viewed from the direction of
any edge

So does Galena or table salt, for that matter, and many others.
Although, if you read the above statement carefully and think about
it, it is nearly nonsense. Who edits these articles?

Wayne

3 
Although, if you read the above statement carefully and think
about it, it is nearly nonsense. Who edits these articles?

Yeah, Wayne, I skimmed through that in about the same way. Pretty
much along the lines of, “I just discovered a new field, I’ll call it
‘crystallography’!!!” Yes, diamond is just a cubic crystal, not the
slightest bit unusual except the carbon atoms are particularly well
bonded.

4 
The type of symmetry and ordered packing displayed by diamond is
not peculiar to diamond at all, and is shared by a few other
minerals. To be fair, Mr. Sunada appears to be a mathematician, not
a mineralogist or crystallographer, but.....

As often happens in popular interpretations of scientific work, the
reporter said things that Dr. Sunada did not. What he said is that
there are only two crystal structures which have both maximal
symmetry and the “strong isotropic” property. He said that diamond is
an example of this crystal structure, but afaict did not say it was
the only such material.