[Source] Slab and Semi polished diamonds

I have been fascinated with the designs using slab and rough
diamonds. Also some designers are using rose cut opaque diamonds. I
would love to include these in my designs. Does anyone know where I
could find reputable dealer for items like these?

Thank you,
Kirsten Reynolds

I have purchased my cubes of natural diamonds from the “Pearl
Goddess”, Betty Sue King. Her store is called “Kings Ransom” She goes
to many shows and gives a great discount for artists that have met
her, especially if you meet at SNAG or the gem show in Tucson. Here
is her web site:

I have never seen “SLAB” diamond. Anyone have a link? My curiosity
is now piqued!


Never heard the term “slab” diamond or really even semi-polished.

Rough. yes, in different forms, octahedral, dodecahedron’s, mackles,

I have many forms, can you clarify?

Roger D. Flanders
Diamond Cutter

Teresa, I’m guessing that “slab diamond” means a macle, which looks
like a triangular slab. Search Google Images for “diamond macle” and
you’ll get images. It’s a fragment from a cleavage, basically.


Try rockdeco.com for rough diamonds.


I'm guessing that "slab diamond" means a macle, which looks like a
triangular slab. Search Google Images for "diamond macle" and
you'll get images. It's a fragment from a cleavage, basically.

Or it could look like this…


Mind you these are created/synthetic. They apparently can do a
polish window (slab like, for a given value of slab) up to 10mm in
diameter in mono crystalline diamond, and bigger in poly-crystalline.
The price though is rather high, like mortgage high.

Cheers, Thomas Janstrom.
Little Gems.

One of the crystal forms diamond in which diamond is found is called
"macle" which is a triangular shape with parallel flat sides.
Diamonds manufactured by the chemical vapor deposition (CVD) process
can also have flat parallel sides. These may be referred to by some
as slab diamonds.

Mike DeBurgh, GJG
Alliance, OH

Sorry, you are correct. It is slice. I was looking at an article in
InStore Magazine December issue and got confused. One of the rings
was described as “polished rough diamond vine ring”, but it has not
been faceted. Another pendant was described as “bezel set
diamond-slice” not slab. The shape of the diamond is square, not
triangular. Also there was a “rose-cut opaque yellow diamond”, very
pretty. I am just interested in something different. Let me know
what you have available.

Sorry, incorrect, a macle is not a cleavage fragment. Its is a rough
diamond that formed from a octahedral face that twisted. If you look
close at one in the middle " where you would see the girdle of a
diamond" you will see a “twinning line” its where the diamond grew in
different directions, very tough to polish. A cleavage piece will not
be the same. Hope this clarifies.

Roger D. Flanders

The shape of the diamond is square, not triangular. 

I’d be happy if any GGs want to expand or correct this…
{Natural} Diamond is a cubic crystal system, and it also has a grain
just exactly like wood does. You can split either one (cleave, in
diamond) along the grain, they must be sawn across the grain.

One form of cubic crystal is a cube - the other form is the
octohedron, which is two four-sided pyramids stuck together at their
bases. The cleavage in the cube is along one of the square sides -
the cleavage on the octohedron is along the pyramid faces. This
cleavage at times happens naturally as the crystals are banged around
in the Earth. So, the cube gives square slices, the octohedron gives
triangular slices - they are both cleavage fragments. Triangular
cleavages are what triangle and trillion stones are cut from, square
cleavages give us princess cuts…

Someone (Thomas?) posted today about synthetic diamond slabs, which
are interesting but I’d guess expensive…

A true macle, as I was was taught, is a twinned crystal. I
understand what a twinned crystal is, but I’ve never grasped how a
macle IS that - I for one would be happy if someone could explain
that in clear terms…

Thanks John. I have only seen the rough cubes & octahedrons in
person, bought a few I have not even used yet, so I was really
curious. Also, I ran into this site:

which sells many different sizes of diamond rough for cutters,
collectors, artist and industrial tool grade as well. Let me tell
you, they have some pretty neat stuff for sale.


A true macle, as I was was taught, is a twinned crystal. I
understand what a twinned crystal is, but I've never grasped how a
macle IS that - I for one would be happy if someone could explain
that in clear terms...... 

Few preliminaries before tackling macle question.

Cube shaped crystals do exist. However, they are so rare that the
crystal itself is more valuable than a diamond faceted from it. I do
not believe they are used to cut diamonds from.

Two commonest crystal forms are octahedron, aka “indian type” and
dodecahedron aka “brazilian type”. Cleavage is always parallel to a
pair of octahedral faces. Since octahedron have 4 such pairs, there
are 4 cleavage directions.

To understand macle, which is a octahedral crystal, half of each was
twisted alongside cleavage plain by 180 degrees, do the following:

take some play dough and fashion an octahedron out of it. with a
knife or a wire separate your octahedron in two parts - separation
line been parallel to any pair pair of parallel octahedral faces.
take one separated part and rotate it 180 degrees. stick both parts
together again and you have your macle.

Leonid Surpin

Thanks John. 

You’re welcome, Teresa. Kenneth Glasser has been the go-to guy for us
little people to buy rough diamond from for decades now - little as
in non sight-holders. Not cheap, but he’s the guy. Didn’t know they
had a website - as Teresa said, it’s

This question may have already been answered; I’ve been away at an
engraving convention.

But just in case, this had been discussed in the past year on this
forum. A TV program was broadcast on ‘NatGeo’, I believe. The US
Bureau of Standards was involved in growing slab diamonds. The big
’to-do’ on this is that these diamonds are very good at conducting
electricity. Whatever it is that causes a diamond to be blue is what
allows diamonds to conduct electricity. So scientists are excited
because this development will allow for faster computers. Less or no
heat. Silicon speed is limited by the amount of heat that builds up.

I am not a scientist, nor a computer ‘geek’ so I can not vouch for
the accuracy of the above. You could look it up. Probably in the
archives of Orchid.


Kenneth Glasser? Gosh, I sure had a lousy experience with him,
though. I had a customer for a 4mm octahedron, for whom I get to make
a cool ring for. Waited 6 months for him to get back in the USA from
Israel. Checked in every so often. Tried to connect with him on
price, what he had, etc, when he got back, then two weeks later,
Poof! he’s gone, back to Israel, and cannot do business. I was livid.

Now I’m going to buy that diamond in Tucson, next week.