Reflected Light
PPL: white color with strong yellow-pink tone, looks like a light orange. Strong pleochroism from orange to pink, with brown-pink tones. 60% reflectivity and distinct bireflectance.
XPL: very strong anisotropy in brown to blue, green to gray.
Images: Nickeline in PPL and in XPL+2º. Gangue dark (PPL) and with yellowish internal reflections (XPL).
PPL: pale copper-red color (intense pink), with a very diagnostic violet hue. Notable pleochroism. Reflectivity 47-54%, with red-pink to violet bireflectance.
XPL: remarkable anisotropy, intense colors: olive, brown, greenish, green, yellowish, etc.
Images: in PPL, breithauptite (pink), rammelsbergite (white), gangue (dark). In XPL, the green anisotropy color of breithauptite and gangue with white internal reflections.
PPL: yellow-brown or light gray yellow color. Distinct pleochroism in gray or brown tones. Reflectivity of 19-29%, with strong bireflectance. Crystals usually very small.
XPL: strong anisotropy between white and bluish. Rare, thin and red internal reflections. Oblique quenching and many polishing grooves.
Images: Chrysocolla(?)(top), tenorite (middle) and cuprite (bottom) in PPL and XPL.
PPL: white to pinkish-brown, similar to tenorite and enargite. No pleochroism. Reflectivity 19 to 23%, with distinct bireflectance.
XPL: strong anisotropy between bluish and gray. No internal reflections. It is associated with native copper, tenorite, cuprite and goethite.
Images: in PPL and XPL, delafossite.
