Beschreibung:

Mintabie, Australia This opal on matrix specimen is from the Mintabie opal field. The opal occurs in Ordovician sandstone as horizontal veins. Occasionally, the veins are too thin for fabricating gemstones, however, when polished on the host rock they show beautiful patterns and displays of color. Fine hairline fissures are natural fractures caused by shrinkage of the opal gel during formation as it slowly solidified and lost its water content. In thicker veins these natural fractures dictate the size of the gemstones. The present specimen possesses a beautiful seam of gemmy opal with excellent play-of-color in orange, green on white matrix. Measuring 15 x 6 x 1 ¾in