Brauns, R. (Reinhard), 1861-1937, Spencer, Leonard James, 1870- · Esslingen a. N. : J. F. Schreiber · leaf 45
r or lower pyramids, the faces intersect the ver- tical axis at a correspondingly greater or shorter distance from the centre than do the faces of the primary form. The symbols of such pyramids must then be 2 P, 3 P , or j P, j P, etc. We may also have square pyramids whose faces intersect in only… … Tetragonal prism of the Tetragonal prism of the The faces of both these tetragonal second order. first order. prisms are inclined at 90°; and the cross- sections of the forms are square, as is also the case with the tetragonal pyramids of both orders. The forms of the first and second orders…
Mineralogy
Internet Archive · Smithsonian Libraries · Public domain (published before 1931). Free to use for anything.
