Optical Calcite
(aka)    "Iceland Spar"
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Museum Specimens

This variety of Calcite is called "Iceland Spar", which is basically clear cleaved fragments of completely colorless (ice-like)
calcite. Originally discovered in and named after Eskifjord, Iceland. The Iceland spar displays the classic cleavage form of
calcite, the rhombohedron. Iceland Spar is used for optical equipment and during World War II it was an extremely important
mineral that was used in the sighting equipment of bombardiers and gunners. Our specimens come from the locations
currently producing the most interesting specimens for collectors. We are always looking for more locales.

“A secret mine in the mountains west of the Salton Sea contained the only available source of a particular calcite crystal
needed to make the famous “Norden Bombsight”.  This transparent crystal formation is also known as Iceland Spar because
it is found in cavities in the solidified lava of which Iceland is made.  The war in Europe had made shipping in the North
Atlantic very precarious and the United States needed another source of this precious commodity.  The Norden bombsight
was one of the most important military secrets of World War II; it made possible the very accurate European bombing raids
which helped bring the war to a close.  It was so advanced that bombardiers had to take an oath to protect its secrecy with
their lives.  Arthur LaLonde remembers that one of his first assignments in the military was to search, with four other men, the
snowy summit of Mt. San Jacinto for the Norden bombsight carried on a plane that had crashed there.  Locals who worked
the mine remember that it was guarded by Marines and worked around the clock.  The mine is now within the boundaries of
Anza-Borrego State Park, north of the Salton City Borrego Springs highway.”
Source:  The Periscope 2001 - Publication of the Coachella Valley Historical Society

Iceland spar demonstrates the unique property of calcite called birefringence (double refraction). Double refraction occurs
when a ray of light enters the crystal and due to calcite's unique optical properties, the ray is split into fast and slow beams.
As these two beams exit the crystal they are bent into two different angles (known as angles of refraction) because the angle
is affected by the speed of the beams. A person viewing into the crystal will see two images ... of everything. The best way to
view the double refraction is by placing the crystal on a straight line or printed word. The result will be two lines or two words
visible through the calcite. The thickness and the angle of the Calcite determines the distance between lines or text as can
be seen in the photos in our listings. Turning or rotating the calcite increases or decreases the space between the two lines
or words (double refraction) that this mineral is famous for. Different sides of the rhomb give different separation  distances
for the double refraction as well. These are very educational and interesting pieces!
Item # 25LOCM03175994
Very Rare 328g Lavender
Optical Calcite from
Madagascar

$1
16.00
Very Rare AAA Grade 328g Lavender Tint Clear Optical Calcite from Madagascar
This specimen measures 3.6 x 2.9 x 1.4 inches (9.1 x 7.4 x 3.6cm) and weighs 11.5oz  or 0.72 lb (328g)

We were happily surprised in our never ending search for quality Optical Calcites when we found these Optical Calcite
Crystal
s from the Mahajanga Province of Madagascar.  We have sold many Optical Calcite Crystals over the past few
years from Mexico, China and Brazil.
The most popular so far have been the Brazilian crystals that are polished with
beveled edges.  The
Optical Calcite crystals from Madagascar are a new find and are not known to most collectors... yet
that is...
we are sure they will become highly sought after very quickly. Madagascar Optical Calcite crystals are the
clearest of
them all and some have very bright rainbow reflections.  Quite a few have a stunning subdued Lavender tint.  
Of all local
es, these are hands down the rarest. Excellent Birefringence.
Item # OCPB02163833
124g Polished Optical Calcite
with Rainbows from Brazil
$79.00
AAA Grade 124g Polished Clear Optical Calcite from Brazil
This specimen measures 1.5 x 1.5 x 1.1 inches (39 x 38 x 28mm) across the flats, or it measures
2.4 x 2 x 1.1 inches (62 x 50 x 28mm) across the diagonals. This piece weighs 4.4oz (124g)

We were lucky in our search for quality Optical Calcite from Brazil when we found this nicely
polished rhomb with lightly rounded chamfered edges that were finished in Brazil. We selected a
few of the nicest pieces and hope to be able to procure more of these excellent specimens in the
future. Polished Optical Calcite is a Real Treasure! Look how well the bi-refraction shows! This
piece is crystal clear and has interesting natural internal fractures. The piece has many amazing
rainbows. A quality work of art direct from Brazil allowing for a lower selling price for a quality
specimen!
Item # 5OCPB02165913
121g Polished Optical Calcite from Brazil

$69.00
AAA Grade 121g Polished Clear Optical Calcite from Brazil
This specimen measures 1.94 x 1.45 x 0.94 inches (49.4 x 36.8 x 23.9mm) across the flats, or it
measures 2.71 x 2.16 x 0.94 inches (68.9 x 54.9 x 23.9mm) across the diagonals.
This piece weighs 4.28oz or 0.267 lb (121g)

We were lucky in our search for quality Optical Calcite from Brazil when we found these nicely
polished rhombs with lightly rounded chamfered edges that were finished in Brazil. We selected a
few of the nicest pieces and hope to be able to procure more of these excellent specimens in the
future. Polished Optical Calcite is a Real Treasure! Look how well the bi-refraction shows! This
piece is crystal clear and has interesting natural internal fractures. The piece is polished on all
sides. A quality work of art direct from Brazil with a lower selling price for a quality specimen!
Item # 3OCPB02165932
108g Polished Optical Calcite from Brazil

$49.00
AAA Grade 121g Polished Clear Optical Calcite from Brazil
This specimen measures 1.52 x 1.25 x 1.23 inches (38.6 x 31.9 x 31.2mm) across the flats, or it
measures 2.16 x 1.73 x 1.23 inches (55 x 44 x 31.2mm) across the diagonals.
This piece weighs 3.8oz or 0.238 lb (108g)

We were lucky in our search for quality Optical Calcite from Brazil when we found these nicely
polished rhombs with lightly rounded chamfered edges that were finished in Brazil. We selected a
few of the nicest pieces and hope to be able to procure more of these excellent specimens in the
future. Polished Optical Calcite is a Real Treasure! Look how well the bi-refraction shows! This
piece is crystal clear and has interesting natural internal fractures. The piece is polished on all
sides. A quality work of art direct from Brazil with a lower selling price for a quality specimen!
Item # 4OCPB02165952
106g Polished Optical Calcite from Brazil

$57.00
AAA Grade 121g Polished Clear Optical Calcite from Brazil
This specimen measures 1.53 x 1.42 x 1.08 inches (38.9 x 36.1 x 27.6mm) across the flats, or it
measures 2.23 x 1.92 x 1.08 inches (56.7 x 48.8 x 27.6mm) across the diagonals.
This piece weighs 3.74oz or 0.234 lb (106g)

We were lucky in our search for quality Optical Calcite from Brazil when we found these nicely
polished rhombs with lightly rounded chamfered edges that were finished in Brazil. We selected a
few of the nicest pieces and hope to be able to procure more of these excellent specimens in the
future. Polished Optical Calcite is a Real Treasure! Look how well the bi-refraction shows! This
piece is crystal clear and has interesting natural internal fractures and rainbows . The piece is
polished on all sides. A quality work of art from Brazil with a great price for a quality specimen!
Item # 51CPB04165953
222g Polished Optical Calcite from Brazil

$79.00
AAA Grade 222g Polished Clear Optical Calcite from Brazil
This specimen measures 2.18 x 1.5 x 1.42 inches (55.5 x 38.2 x 36.1mm) across the flats, or it
measures 2.98 x 2.41 inches (75.7 x 61.3mm) across the diagonals.
This piece weighs 7.8oz or 0.49 lb (222g)

We were lucky in our search for quality Optical Calcite from Brazil when we found these nicely
polished rhombs with lightly rounded chamfered edges that were finished in Brazil. We selected a
few of the nicest pieces and hope to be able to procure more of these excellent specimens in the
future. Polished Optical Calcite is a Real Treasure! Look how well the bi-refraction shows! This
piece is crystal clear and has interesting natural internal fractures and rainbows . The piece is
polished on all sides. It has a few corner dings as shown in the photos, still an amazing
specimen! A quality work of art from Brazil with a great price for a quality specimen!
Item # 52CPB04165953
204g Polished Optical Calcite from Brazil

$72.00
AAA Grade 204g Polished Clear Optical Calcite from Brazil
This specimen measures 1.82 x 1.59 x 1.53 inches (46.4 x 40.5 x 39mm) across the flats, or it
measures 2.69 x 2.11 inches (68.3 x 53.7mm) across the diagonals.
This piece weighs 7.2oz or 0.45 lb (204g)

We were lucky in our search for quality Optical Calcite from Brazil when we found these nicely
polished rhombs with lightly rounded chamfered edges that were finished in Brazil. We selected a
few of the nicest pieces and hope to be able to procure more of these excellent specimens in the
future. Polished Optical Calcite is a Real Treasure! Look how well the bi-refraction shows! This
piece is crystal clear and has interesting natural internal fractures and rainbows . The piece is
polished on all sides. It has a few corner dings as shown in the photos, still an amazing
specimen! A quality work of art from Brazil with a great price for a quality specimen!
Item # 26LOCM03175992
Very Rare 171g Lavender
Optical Calcite from Madagascar

$6
9.00
Very Rare AAA Grade 171g Lavender Tint Clear Optical Calcite from Madagascar
This specimen measures 2.8 x 2.3 x 1.1 inches (7.2 x 5.8 x 3cm) and weighs 6oz  or 0.37 lb (171g)

We were happily surprised in our never ending search for quality Optical Calcites when we found these Optical Calcite
Crystals from the Mahajanga Province of Madagascar.  We have sold many Optical Calcite Crystals over the past few
years from Mexico, China and Brazil. The most popular so far have been the Brazilian crystals that are polished with
beveled edges.  The Optical Calcite crystals from Madagascar are a new find and are not known to most collectors... yet
that is... we are sure they will become highly sought after very quickly. Madagascar Optical Calcite crystals are the
clearest of them all and some have very bright rainbow reflections.  Quite a few have a stunning subdued Lavender tint.  
Of all locales, these are hands down the rarest. Excellent Birefringence
Item # 27LOCM03175913
Very Rare 163g Lavender
Optical Calcite from Madagascar

$7
6.00
Very Rare AAA Grade 163g Lavender Tint Clear Optical Calcite from Madagascar
This specimen measures 2.8 x 2.3 x 1.1 inches (7.1 x 6 x 3cm) and weighs 5.7oz  or 0.36 lb (163g)

We were happily surprised in our never ending search for quality Optical Calcites when we found these Optical Calcite
Crystals from the Mahajanga Province of Madagascar.  We have sold many Optical Calcite Crystals over the past few
years from Mexico, China and Brazil. The most popular so far have been the Brazilian crystals that are polished with
beveled edges.  The Optical Calcite crystals from Madagascar are a new find and are not known to most collectors... yet
that is... we are sure they will become highly sought after very quickly. Madagascar Optical Calcite crystals are the
clearest of them all and some have very bright rainbow reflections.  Quite a few have a stunning subdued Lavender tint.  
Of all locales, these are hands down the rarest. Excellent Birefringence  
Displays rainbow colors!
Item # 28LOCM03175912
Very Rare 29g Lavender Optical
Calcite from Madagascar

$3
6.00
Very Rare AAA Grade 29g Lavender Tint Clear Optical Calcite from Madagascar
This specimen measures 1.5 x 1.2 x 0.75 inches (3.8 x 3.2 x 1.9cm) and weighs 1oz (29g)

We were happily surprised in our never ending search for quality Optical Calcites when we found these Optical Calcite
Crystals from the Mahajanga Province of Madagascar.  We have sold many Optical Calcite Crystals over the past few
years from Mexico, China and Brazil. The most popular so far have been the Brazilian crystals that are polished with
beveled edges.  The Optical Calcite crystals from Madagascar are a new find and are not known to most collectors... yet
that is... we are sure they will become highly sought after very quickly. Madagascar Optical Calcite crystals are the
clearest of them all and some have very bright rainbow reflections.  Quite a few have a stunning subdued Lavender tint.  
Of all locales, these are hands down the rarest. Excellent Birefringence