Carpenters often cut wood at the construction site. Carpenters construct and repair building frameworks and structuresâsuch as stairways, doorframes, partitions, rafters, and bridge supportsâmade from wood and other materials. They also may install kitchen cabinets, siding, and drywall.
Beryllium is a chemical element with symbol Be and atomic number 4. It is a relatively rare element in the universe, usually occurring as a product of the spallation of larger atomic nuclei that have collided with cosmic rays. Within the cores of stars beryllium is depleted as it is fused and creates larger elements. It is a divalent element which occurs naturally only in combination with other elements in minerals. Notable gemstones which contain beryllium include beryl (aquamarine, emerald) and chrysoberyl.
Beryl is a mineral composed of beryllium aluminium cyclosilicate with the chemical formula Be3Al2(Si O3)6. Well known varieties of beryl include emerald and aquamarine. Naturally occurring, hexagonal crystals of beryl can be up to several meters in size; terminated crystals are relatively rare. Pure beryl is colorless, but it is frequently tinted by impurities; possible colors are green, blue, yellow, red, and white.