Acicular synonyms

The difference between schists and gneisses is mainly that the latter have less highly developed foliation; they also, as a rule, are more coarse grained, and contain far more quartz and felspar, two minerals which rarely assume platy or acicular forms, and hence do not lead to the production of a fissile character in the rocks in which they are important constituents.

As found in nature, saltpetre generally forms aggregates of delicate acicular crystals, and sometimes silky tufts; distinctly developed crystals are not found in nature.

It dissolves in water with evolution of heat; on evaporation a basic salt, ZrOC1 2.8H 2 0, separates out in star-shaped acicular aggregates.

Iodine dissolves in an aqueous solution of the salt to form a dark brown liquid, which on evaporation over sulphuric acid gives black acicular crystals of the tri-iodide, K1 3.

Elongated, cylindrical, rounded at both ends; thick cuticle with acicular spicules; radula polystichous or wanting.