Polyhedroid Agates Page 1
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       (center top specimen photo from 2009 Gem Shop Calender)
Polyhedroid Agates are one of nature’s great unexplained formations. These geometric beauties were only found for a short time in
the 1970’s and only in one location in the world. It is fitting that some of the most desirable agates in the world come from the
greatest agate producing country, that being Brazil. These were located in Paraiba the only state in Brazil that ever produced any of
these specimens. These stunning agates formed in geometric pattern shapes rather than the more common round or oval agate
shape. The theories of formation of these agates are still an ongoing evaluation among geologists. The most agreed upon formation
theory seems to be that the sharp geometric shapes are thought to have been formed in the voids between interlaced crystals of
Barite, or possibly Calcite crystal formations.
The agate nodules can be solid or hollow and the best grades have distinct, colorful fortification agate bands that follow the typically
triangular or trapezoidal shape of the Polyhedroid Agate. They are some of the highest quality agates available, and are able to be
polished to the highest mirror glaze finish that quality agates can obtain. These agates rarely have fractures or other imperfections.
Most nodules are quartz with black, gray, white being the predominant colors of the Polyhedroid agates. Shapes can be a variety of
geometric forms with the equilateral triangle shape being the most desirable shape. (One cannot help but wonder if Euclid, the
father of Geometry found some of these agates or maybe nature made these just to prove Euclid’s theorems.) The Polyhedroid
Agate makes the best agate show piece and conversation piece in any collection. These are very rare and expensive….but like they
say…”You get what you pay for!”  Polyhedroid Agates are our favorites!
We have spent the better part of the last 14 years procuring Polyhedroid
specimens from all over the world. We Have sold a few polished ones from time to
time. As we get older we are realizing that we probably will never be able to cut
and polish all the wonderful Polyhedroid Agates we have collected, so we have
decided to sell off a large portion of what we have collected.

We will be listing here Polyhedroid Agates which are geometrically shaped, mostly
with quartz centers, but can have small agate banding in the center. We will also
be listing some smaller good to AA grade (Jewelry grade) agates. These sell
priced on current market.

When these agates are light colored on the outside, the interior will mostly be
clear quartz. The amount of darkness in the exterior skin will give you an idea of
how much grey or black shading is inside these rare agates. If you look at the
photos above and at our listings you will see the wide array of possibilities for the
interiors of these agates. You never know until you cut one open what surprises
lie hiding inside. We have always been fascinated with Brazilian Agates and we
feel very lucky to have some to offer you for your collection and for you to cut and
polish.

We have also come across a matrix specimen which shows the Polyhedroid agate
formation in crystalline calcite, supporting the current best formation theories. You
can see the calcite blades and agate shapes pointed out with the arrows in the
photo shown on the left. (this specimen has been sold)

This specimen was photographed wet and has had the contrast increased
and has been darkened to better show the polyhedroid agate formations
and calcite plate formations in this face cut matrix specimen from Paraiba
Sequential cut Pair of Triangular Polyhedroid Agate Rough Slabs from Paraiba Brazil
This is a rough cut pair of Polyhedroid Agate slabs of jewelry grade suitable for making a pair of earrings. Shown
dry. These slabs were cut one after the other in sequence and are as close to possible of being a matched pair
These are an Exceptionally Rare Polyhedroid specimen pair which show an excellent pattern when back-lit or when
polished.
These specimens weigh
1g and measures 18.8 x 8.9 x 3.7mm and 1g and measures 21.7 x 10.9 x 2.9mm
Item # 51PHA11182900
Exceptionally Rare Jewelry Grade
Polyhedroid Agate Pair rough cut slabs

$30.00
Quantity Available 1pair
Polyhedroid Agates in Matrix from Paraiba Brazil
This is the specimen we picked up years ago. It is a piece of the matrix from Paraiba, Brazil. When it was cut, a few
Polyhedroid Agates become visible. The specimen was sealed on the cut face to preserve the integrity of the agate
formation in calcite blade structure. This is the specimen we show at the top of this page.
This specimen weighs 5.7 oz or 0.35 lb (161g) and measures 3 x 1.75 x 1.3 inches (78 x 44 x 35mm)
There is a quadrilateral (almost trapezoidal) agate who's face measures 2.1 x 0.7" (53 x 18mm) and a small kite like
agate that measures 19.5 x 5.9mm easily seen in the photos.
Item # 23PHA04146551
Polyhedroid Agates in Matrix
Polyhedroid Display Specimen from Paraiba Brazil
This is an Extra Large 1.81 lb "Old Stock" piece from our collection. This was cut and polished in our shop. There is a
nice Triangular Crystalline Face with a small center agate lined vug with drusy quartz crystals inside. This piece shows
the 3 pattern seams in the crystal from the inner triangle vug to the outer skin points. The crystal face also indicates a
possible darker center fill deeper in the agate. This agate has natural angles on the sides which allow for three different
90 degree face displays or about 45 degrees on the back which makes this one a nice natural display specimen. This
could also be cut into slabs  The photos show its different faces and angles.
This specimen weighs 28.9 oz or 1.81 lb (822g)
and measures 4.3 x 3.3 x 3.6 to 1.9 inches (11 x 8.4 x 9.2 to 4.9cm)
Item # 1PHA121605201
Rare Old Stock Polished Face
Polyhedroid Agate Display Specimen

$295.00
We are always looking for Polyhedroid Agates. Some
just for display and some Jewelry Grade Polyhedroids.
We will be listing them as we a
re able to locate them.
Cut and Polished in our
Work Shop!
Triangular Polyhedroid Agate Specimen from Paraiba Brazil
This is a Triangular (3 straight sides) Polyhedroid Agate Specimen from our
collection. This piece is not polished and is shown dry. This amazing piece has
clear crackle appearance quartz with a black-grey band in the center of the quartz
band. The interior vug chalcedony forms to a stunning botryoidal interior.

This specimen weighs 1.76 oz (50g)
and measures 3.5 x 2.5 x 0.26 inches (89 x 64 x 6.7mm)
Item # 2PHAS02188830
Triangular Polyhedroid Agate Slab (Not Polished)

$35.00
Triangular Polyhedroid Agate Specimen from Paraiba Brazil
This is a Triangular (3 straight sides) Polyhedroid Agate Specimen from our
collection. This piece is not polished and is shown dry. This amazing piece has
clear crackle appearance quartz with a black-grey band in the center of the quartz
band. The interior vug chalcedony forms to a stunning botryoidal interior.

This specimen weighs 1.62 oz (46g)
and measures 3.2 x 2.4 x 0.26 inches (81 x 61 x 6.6mm)
Item # 3PHAS02187530
Triangular Polyhedroid Agate Slab (Not Polished)

$35.00
Triangular Polyhedroid Agate Specimen from Paraiba Brazil
This is a Triangular (3 straight sides) Polyhedroid Agate Specimen from our
collection. This piece is not polished and is shown dry. This amazing piece has
clear crackle appearance quartz with a black-grey band in the center of the quartz
band. The interior vug chalcedony forms to a stunning botryoidal interior.

This specimen weighs 1.3 oz (37g)
and measures 3.1 x 2.2 x 0.23 inches (79 x 57 x 6mm)
Item # 4PHAS02187820
Triangular Polyhedroid Agate Slab (Not Polished)

$35.00
Triangular Polyhedroid Agate Specimen from Paraiba Brazil
This is a Triangular (3 straight sides) Polyhedroid Agate Specimen from our
collection. This piece is not polished and is shown dry. This amazing piece has
clear crackle appearance quartz with a black-grey band in the center of the quartz
band.

This specimen weighs 1.12 oz (32g)
and measures 32.8 x 2.1 x 0.24 inches (71 x 54 x 6.1mm)
Item # 5PHAS02188420
Triangular Polyhedroid Agate Slab (Not Polished)

$30.00
Triangular Polyhedroid Agate Specimen from Paraiba Brazil
This is a Triangular (3 straight sides) Polyhedroid Agate Specimen from our
collection. This piece is not polished and is shown dry. This amazing piece has
clear crackle appearance quartz.

This specimen weighs 12.5g
and measures 1.8 x 1.3 x 0.21 inches (47 x 33 x 5.4mm)
Item # 10PHAS021867900
Triangular Polyhedroid Agate Slab (Not Polished)

$17.00
Triangular Polyhedroid Agate Specimen from Paraiba Brazil
This is a Triangular (3 straight sides) Polyhedroid Agate Specimen from our
collection. This piece is not polished and is shown dry. This amazing piece has
clear crackle appearance quartz.

This specimen weighs 9.5g
and measures 1.6 x 1.1 x 0.20 inches (42 x 30 x 5.2mm)
Item # 11PHAS02184700
Triangular Polyhedroid Agate Slab (Not Polished)

$16.00
Triangular Polyhedroid Agate Specimen from Paraiba Brazil
This is a Triangular (3 straight sides) Polyhedroid Agate Specimen from our
collection. This piece is not polished and is shown dry. This amazing piece has
clear crackle appearance quartz.

This specimen weighs 7.5g
and measures 1.4 x 1 x 0.23 inches (35 x 26 x 5.9mm)
Item # 12PHAS02188500
Triangular Polyhedroid Agate Slab (Not Polished)

$15.00
Polyhedroid Agates Page 2
Sequential cut Pair of Triangular Polyhedroid Agate Rough Slabs from Paraiba Brazil
This is a rough cut pair of Polyhedroid Agate slabs of jewelry grade suitable for making a pair of earrings. Shown
dry. These slabs were cut one after the other in sequence and are as close to possible of being a matched pair
These are an Exceptionally Rare Polyhedroid specimen pair which show an excellent pattern when back-lit or when
polished.
These specimens weigh
1g and measures 25 x 12.4 x 2.9mm and 1.5g and measures 26.7 x 14.1 x 2.9mm
Item # 52PHA11185110
Exceptionally Rare Jewelry Grade
Polyhedroid Agate Pair rough cut slabs

$30.00
Quantity Available 1pair
Triangular Polyhedroid Agate Rough Slab from Paraiba Brazil
This is a rough cut Polyhedroid Agate slab of jewelry grade suitable for making a
pendant or a brooch. Shown dry. This slab is an Exceptionally Rare Polyhedroid
specimen which shows an excellent pattern when back-lit or when polished..
This specimens weighs 3.5g and measures 33.2 x 15.9 x 4.5mm
Item # 53PHA11180610
Exceptionally Rare Jewelry Grade
Polyhedroid Agate rough cut slab

$30.00
Quantity Available 1each
Triangular Polyhedroid Agate Rough Slab from Paraiba Brazil
This is a rough cut Polyhedroid Agate slab of jewelry grade suitable for making a
pendant or a brooch. Shown dry. This slab is an Exceptionally Rare Polyhedroid
specimen which shows an excellent pattern when back-lit or when polished..
This specimens weighs 4g and measures 36.4 x 18 x 4.6mm
Item # 54PHA11182810
Exceptionally Rare Jewelry Grade
Polyhedroid Agate rough cut slab

$30.00
Quantity Available 1each
Triangular Polyhedroid Agate Rough Slab from Paraiba Brazil
This is a rough cut Polyhedroid Agate slab of jewelry grade suitable for making a
pendant or a brooch. Shown dry. This slab is an Exceptionally Rare Polyhedroid
specimen which shows an excellent pattern when back-lit or when polished..
This specimens weighs 3g and measures 39.6 x 19.9 x 2.9mm
Item # 55PHA11189310
Exceptionally Rare Jewelry Grade
Polyhedroid Agate rough cut slab

$39.00
Quantity Available 1each
Sequential cut Pair of Pentagon Polyhedroid Agate Rough Slabs from Paraiba Brazil
This is a rough cut pair of Polyhedroid Agate slabs of jewelry grade suitable for making pendants or necklaces.
Shown dry. These slabs were cut one after the other in sequence and are as close to possible of being a matched
pair These are an Exceptionally Rare Polyhedroid specimen pair which show an excellent pattern when back-lit or
when polished.
These specimens weigh
9g and measures 44 x 30.2 x 4.5mm
and 8.5g and measures 44.2 x 29.5 x 4.5mm
Item # 50PHA11187970
Exceptionally Rare Jewelry
Grade Polyhedroid Agate Pair
rough cut slabs

$30.00
Quantity Available 1pair