cibinic alkaline igneous rock geology rock texture decorative

acmite aegirine aegirineaugite aggregate albite alkaline background black brown brownblack cleavage clinopyroxene closeup collection crystal crystalline feldspar gemology gemstone geological geology granite greenishblack khibiny kola little macro mineral monoclinic natural nature object ore pebble peninsula piece prismatic raw rock sample silicate small specimen spherulite stone structure surface syenite textured white