Black opal (Black and Dark opal or semi-black) - the color of the base material is black, semi-black, dark gray to light gray. Coloring is due to the presence of carbonaceous substances in the molecular structure. It features a number of beautifully opalescent rich colors highlighted with black or dark backgrounds. It is always accompanied by a general opal, the so-called "dots" (the same color as the base mass). black opal is found in layers of clay.
Natural precious opal from Australia (Lightning Ridge) 12,2x6,7x2,7mm, 1,36ct
Natural precious opal from Australia (Lightning Ridge) 14,7x9,4x3,4mm, 2,71ct
Natural precious opal from Australia (Lightning Ridge) 15,9x10,3x3,4mm, 3,59ct
Natural precious opal from Australia (Lightning Ridge) 10,4x5,7x3mm, 1ct
Natural precious opal from Australia (Lightning Ridge) 10,5x6,4x2,5mm, 1,1ct
Natural precious opal from Australia (Lightning Ridge) 10x5,6x2,6mm, 0,86ct
Natural precious opal from Australia (Lightning Ridge) 8,5x7,7x3,7mm, 1,34ct
Natural precious opal from Australia (Lightning Ridge) 8x5,3x3,8mm, 0,82ct
Natural precious opal from Australia (Lightning Ridge) 11,7x3,5x2,4mm, 0,64ct
Natural precious opal from Australia (Lightning Ridge) 11,4x7,3x2mm, 0,97ct
Natural precious opal from Australia (Lightning Ridge) 9,8x9,3x2,9mm, 1,6ct
Natural precious opal from Australia (Lightning Ridge) 12x10,4x3,5mm, 3ct
Natural precious opal from Australia (Lightning Ridge) 15,2x11,2x3,5mm, 3,6ct
Natural precious opal from Australia (Lightning Ridge) 16,8x10,2x3,6mm, 4ct
Natural precious opal from Australia (Lightning Ridge) 19,5x14,3x3mm, 4,7ct
Natural precious opal from Australia (Lightning Ridge) 10,5x8,2x2,2mm, 1ct
Natural precious opal from Australia (Lightning Ridge) 23,8x11x3,5mm, 6ct
Natural precious opal from Australia (Lightning Ridge) 14,3x11,9x3mm, 3,5ct
Natural precious opal from Australia (Lightning Ridge) 8,5x7,6x1,8mm, 0,7ct
Natural precious opal from Australia (Lightning Ridge) 14x9x2,6mm, 2ct
Natural precious opal from Australia (Lightning Ridge) 12,2x8,1x2,2mm, 1,4ct
Natural precious opal from Australia (Lightning Ridge) 11x10,6x3,7mm, 3ct
Natural precious opal from Australia (Lightning Ridge) 11,9x5,3x2,8mm, 1,3ct
Natural precious opal from Australia (Lightning Ridge) 12,8x12,3x4,2mm, 4,3ct
Natural precious opal from Australia (Lightning Ridge) 13,3x12x4mm, 3,6ct
Natural precious opal from Australia (Lightning Ridge) 8,5x6,7x1,7mm, 0,65ct
Natural precious opal from Australia (Lightning Ridge) 26,9x13,9x4mm, 8ct
Natural precious opal from Australia (Lightning Ridge) 18,7x8,3x3,7mm, 3,65ct
Natural precious opal from Australia (Lightning Ridge) 16,3x7,4x2,6mm, 2ct
Natural precious opal from Australia (Lightning Ridge) 9x7,8x5mm, 2ct
Natural precious opal from Australia (Lightning Ridge) 16,9x11,5x2,9ct, 3,4ct
Natural precious opal from Australia (Lightning Ridge) 13x9,8x2,9mm, 2,22ct
Natural precious opal from Australia (Lightning Ridge)...