Your wife could have been exposed to a number of things not
necessarily in the jewelry business.
Asbestos is less dangerous when in a "solid" form or "contained" in
some way, for example kilnlining or roof and wall tiles. It's when
the fibers come free and are dispersed in the air we breathe it
becomes very dangerous. Think brakelinings as they are worn down or
ventilation shafts. Asbestos based poducts were popular in the
building sector because of their low cost and durability. Asbestos
in investment is a definite health hazard, a soldering board not as
much. Tailors used heatprotective asbestos slabs under their irons.
When tearing down old buildings all materials containing asbestos
has to be identified and removed by workers certified for this.
Unfortunately asbestos used to be all around us.