following information comes from the web site of the Vaseline
Glass Collectors Inc.(VGCI), a non-profit organization incorporated
in 1998 to educate and unify Vaseline Glass collectors everywhere.
For more information about vaseline glass and the collecting
of vaseline glass, please visit the official web site for the
only organization dedicated to educating and unifying vaseline
glass collectors everywhere, www.vaselineglass.org.
In general, "uranium glass" is defined as any glass which
contains a depleted form of uranium, uranium oxide, a component of
the glass formula that gives the glass a special fluorescent character
and is a term heard most frequently in the British world of glass
including Australia and New Zealand. Vaseline glass is another term
for glass containing uranium oxide that is the term most frequently
heard in the United States for uranium glass.
However, as is often the case, definitions can be confusing: some
authorities consider vaseline glass to be yellow or yellow-green (depending
on if it is in indoor or incandescent light or daylight). The glass
can look yellow under incandescent lighting, but outdoors, the UV
of the sun will stimulate the atoms, making the same piece look yellow-green.
Also, when a flash camera is used on vaseline glass, it will make
it appear more green than the eyes do, because the intense flash also
stimulates the uranium atoms.
Vaseline glass (in the USA) is defined by the VGCI to be yellow first
and glow green under a blacklight second. Other countries have their
own definition for vaseline glass. For instance, people in Australia
use the words, 'vaseline glass' for any type of glass that has an
opalescent rim. What we consider (in the USA) to be vaseline glass,
they call citron or uranium glass. The British in the United Kingdom
refer to glass that has a whispy opalescent treatment to be vaseline
glass. What they call 'Primrose Pearline' (a trade name from Geo.
Davidson & Son) is what the US collectors call 'vaseline glass'. In
Germany, they did not differentiate and call all of it 'uranglas'
and it can be yellow or green, as long as it has uranium in it and
glows under a blacklight.
Many sellers describe any green depression glass as "vaseline
glass," knowing that vaseline glass brings more money than green
depression glass. True vaseline glass does not have iron oxide added
to the formula, which makes green depression glass a separate formula,
and thus, is not considered to be vaseline glass.
Let it be stated here and now that although uranium or vaseline glass
does contain depleted uranium oxide and thus does give off a small
amount of radioactivity, it is considered safe by authorities including
the Atomic Energy Commision and other governmental authorities controlling
the use and sale of uranium. Remember, some small degree of radiation
is a part of our natural environment including the brick in brick
buildings. The amount of radioactivity in uranium glass is equivalent
to this "background level" of radioactivity and does not
pose a health threat.