Connecticut, U.S.A. The best known localities are Glastonbury,
where the uraninite is found in the feldspar quarries, and
Branchville, where it occurs in an albitic granite. Both of these
localities have furnished fine crystals. The geological period probably
corresponds with the close of the Ordovician or Carboniferous eras, and
is stated to be certainly Post-Cambrian and Pre-Triassic. Among the
associated minerals are (primary) columbite, (secondary) torbernite
and autunite.
Southern Norway, particularly in the neighbourhood of Moss.
Here uraninite occurs in the augite-syenite and pegmatite. The
varieties found are known as cleveite and bröggerite, and among the
primary associated minerals are orthite, fergusonite, monazite, and
thorite. The period is stated to be Post-Devonian.
Llano County, Texas. The variety of uraninite known as nivenite is found here in a quartzose pegmatite,