( Fr- larvikite; Ger- Larvikit; Nor- larvikitt; Rus- )
LARVIKITE (also spelled laurvikite)
A. Larvikite, two larger blocks, usually marketed as "Norwegian Pearl granite." In some marketplaces, the lighter variety (left) is called "Blue Norwegian moonstone" and the darker variety (right) as "Royal blue pearl granite" or "Emerald pearl ..." The small piece (height - 3.5 cm) on top of the left block is anorthosite (see ANORTHOSITE entry); it is included for comparison of chatoyancies. R.V. Dietrich collection. (© photo by Dick Dietrich)
DESCRIPTION: Larvikite is the name applied
widely to relatively coarse-grained anorthoclase-rich igneous rocks
from the vicinity of Larvik, Norway. Anorthoclase
constitutes 90 or more per cent of most of these rocks, is , for all
practical purposes, an
intimate, submicroscopic intermixture of a plagioclase and an alkali
feldspar. In petrographic circles this rock has been equated with
both alkalic syenite and monzonite. Larvikite has the following
Color - light to dark bluish gray with two more-or-less distinct varieties -- one light bluish gray, the other dark bluish gray with golden brown overtones
H. 6 - 6½
Light transmission - translucent (in thin pieces) to opaque
Luster - overall pearly to subvitreous
Miscellany - in essence larvikite is a light to dark gray coarse grained feldspar-rich grock that exhibits light blue "flashlike reflections" on some surfaces; the reflections, which come from individual anorthoclase grains that exhibit a chatoyant-like appearance, are frequently referred to as a pearl-gray iridescence, opalescence, or even labradorescence (in allusion to the appearance of labradorite -- see ANORTHOSITE entry).
OTHER NAMES: Larvikite has many
trade names: Birds eye granite, Black moonstone, Blue Norwegian moonstone, Blue
pearl granite, Blue granite, Blue antique, Blue pearl, Blue pearl
fjord, Emerald pearl, "Labradorite," Larvik granite, Marina
blue star, Norwegian pearl granite, Norwegian moonstone and Royal blue
pearl granite are those I have seen. As is apparent, some of
these name are unfortunate misnomers, particularly from the standpoint
that terms like granite are included; certainly larvikite is not
a granite in the laguage of petrography and it is hardly such in the
usual sense of the word as used in the building/monument stone
Along with the just mentioned names, my attention
was recently directed to another name for larvikite -- one I cannot
resist adding here: "Publich-houseite"
(or "pub stone")
is a nickname given larvikite in parts of Great Britain "because it is
so common as a facing stone in British Pubs!" (www.bbc.co.uk/education)
Two chief variants of Larvikite are widely
recognized because they direct attention to the overall color of those
rocks. Personally, I -- and I have studied these rocks(!)
-- fail to understand the basis of using the "emerald"
designation. In any case, the two overall terms commonly applied
USES: The major use of larvikite is as an exterior and interior facing stone, and, indeed, it is a very popular one the world over. However, larvikite has also been fashioned for use as a gemstone and into several ornamental and functional items. Examples are: cabochons, free forms, and tumbled stones for pendants, brooches and other jewelry; paper weights and bookends; knobs for cabinet drawers and doors; eggs and spheres; and small carvings and relatively large sculptures.
OCCURRENCES: Relatively large masses, generally considered to be of igneous origin.
NOTEWORTHY LOCALITIES: Several active and
abandoned quarries, each with its special variant of larvikite, are in
the vicinity of Larvik, southern
A story about larvikite, which I
have heard several people repeat but have been unable to verify, holds
that larvikite first came on to the market as the result of a chance
request made of the Norwegian group who were corresponding with the
a World's Fair held in Germany in the early 1890s. According to
that story, each
country scheduled to have an exhibit or otherwise participate in the
fair's activities was asked to send two of its decorative facing
stones, to be judged by a panel of architects. Apparently at that
time, Norway was only producing one facing stone, so the national
committee -- not wanting to admit it -- asked Dr. Brögger to
suggest a second
rock that could be prepared and sent to the fair.
Brögger is said to have answered, with no hesitation, that he
thought the rock that winked at him in the moonlight as he rode in his
buggy beside exposures along the La(u)rvik Fjord would be a good
choice. So, a slab of this rock was prepared, transported, displayed at
AND voted the finest rock exhibited. -- True or not, La(u)rvikite has
become a widely used decorative and facing stone during the last
century plus, and today it can be
and there throughout the world.
Largely because of
their overall color, grainsize or the presence or lack of preferred
orientation of their component grains, some variants of larvikite have
been found to be better suited for certain uses and ill-suited for
other uses. Along this line, their trade names, given under the OTHER
NAMES subheading, and statements about the different variants that are
available from distributers are noteworthy.
As just mentioned,
Larvikite can be seen as a facing stone on exterior and interior
surfaces of buildings throughout the world. Examples range from
its use in the United Nations building in New York City to counter tops
in many private homes. One of my favorite uses, however, is the
sculped so-to-speak modernistic bust of Thor Heyerdahl
fame that is in Larvik. The setting, the form, and the use of
larvikite all seem most appropriate considering the man and the fact
that he was a native of Larvik.
is described as "Norges nasjonalstein" (i.e., the national stone of N
orway) in several recent publications (Børresen and Heldal,
2009). To date, I have not found if it has or has not been
so-designated by any official act of the Norwegian government.
Anorthosite - although some anorthosites resemble la(u)rvikite and could be used as simulates, I have found no evidence that any anorthosite has ever been represented as a substitute for la(u)rvikite used as a gemrock.
REFERENCE: Barth, 1944; Børresen and Heldal, 2009.
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