I am making small plaster molds. I don't plan on painting over the plaster with paint. What would be a good seal to prevent plaster dusting off or dirt getting in the pores? This is for jewelry. Will shellac or mod podge work fine?

Match Term Definition
Talc can be scratched by most other minerals. A) hardness
Mica is a mineral that splits evenly and forms sheets. B) luster
Hematite leaves a rust colored trail of dust when it is rubbed on an unfinished ceramic tile. C) cleavage
Pyrite shines like gold and is called fools gold because of this trait. D) streak
Emeralds are green and are popular minerals for use in jewelry. E) color

Scientists have used a combination of relative dating and absolute dating techniques to create the__________, the "map" of past eras of earth's history.

In 1957, the Russian satellite, __________was launched. This event began what we now call the "Space Race" between the US and Russia.