|The composition of the pegmatite’s is,
as said above, relatively simple. Publications about Byrud are
scarce, incomplete and outdated. Actually, the most comprehensive
description dates back from 1911, a small chapter in V.M.
Goldschmidt’s “Die Kontaktmetamorphose im Christianiagebiet”. G.
Raade & J. Haug have a comprehensive publication in preparation.
I base the systematic description in the first place on Goldschmidt
and my own observations.
The sulfides are represented by pyrite, pyrrhotite
and molybdenite. The quantity of sulfide minerals is
minimal, and none of them occurs as collectable specimens.
Pyrrhotite occurs as bronze-brown massive mineral. Every now and
then, when breaking up material in search of good micro-crystals of
emerald, 6-sided plates of molybdenite, less than 1 mm in size, are
The halogenides are represented by fluorite only, and
cannot be considered to be of major interest to collectors.
Colorless to purple masses of fluorite are found widespread in small
quantities. I was informed that crystals have been found, but that
these are quite rare.
The oxides are represented by ilmenorutile, which occurs
sparingly but widespread, as small 1-5 mm, metallic black crystals.
The idenitification is based on a personal communication. The habit
of the crystals is generally blocky, and because the crystals are
generally embedded in feldspar, it is often impossible to determine
the faces at the crystals. Free-grown crystals in miaroles are
The silicates are the largest group, and are represented by
albite, bavenite, beryl,
microcline/orthoclase, muscovite (often as
“sericite”), quartz and topaz.
Albite, microcline/orthoclase, muscovite
and quartz are of little interest to collectors.
Bavenite occurs as radiating groups of white/colorless,
thin-tabular, prismatic crystals of max. 1-2 mm’s in miarolitic
cavities in the feldspar. Bavenite is rare.
Beryl is by far the most spectacular mineral. The color
varies from yellow, green to intensive blue. The majority of the
beryl is found as emerald in all kind of shades of green. From pale
to intensive green, from translucent to absolutely clear. Large
emerald crystals of true gem quality are nowadays extremely rare,
and I found only one. But small emerald crystals up to 5 mm of
length and with a thickness of 1-2 mm of gem quality are not really
hard to find. Especially nice are the even smaller, free-standing
emerald crystals in miarolitic cavities in the feldspar. Important
detail, is that the coloring agent in the beryl from Byrud is
vanadium, and not chromium. The vanadium is derived from the shale’s
in which the pegmatite’s were injected, and which contain a
significant amount of this element. Blue colored beryl -aquamarine-
is very rare at Byrud: after several visits I found no more than 2
Topaz is after beryl the most interesting mineral from
Byrud. The mineral is definitely not rare, but is easily overseen by
collectors who concentrate on finding emeralds. Often you will find
large masses of small, colorless, intergrown topaz-crystals. With a
bit of luck you might manage to prepare a couple of complete,
well-developed crystals outof such pieces. The average size of such
crystals is around 0,5 till 1 cm, but occasionally crystals up to
3-4 cm can be found. Very rare are free-standing topaz-crystals in
miarolitic cavities of the pegmatite. I have been witness to someone
finding a waterclear, perfectly developed 1,5 cm crystal some years
ago. Characteristic forms of the topaz-crystals are (110), (011) and
(001), but a multitude of additional forms may be observed on