A seam or patches of precious opal still attached to the host rock in which the opal formed. Highly valued and sought after for its brilliant colors and patterns. Most boulder opal is mined in Queensland, Australia. View our complete range of Boulder Opal.
Presented in one piece where the Opal is naturally attached to the host rock in which it was formed
is distinguished by the presence of host brown rock, usually ironstone, on the back of the opal; and is found almost exclusively in Queensland.
This bright and beautiful stone comes from Queensland, Australia. It forms naturally on another rock called ironstone. Boulder Opal has a body color that is darker than traditional opal, and its play of colors are generally more intense and vivid. Boulder Opal has the look of very rare and coveted Black Opal.
Opal found within very hard ironstone concretions of varying shapes and sizes.
Is not from Colorado, but from Queensland, Australia. It's composed of veins of opal in a red-brown host rock called ironstone, (which can sometimes be found in boulders). It has the particular advantages of durability, and POC shows up better on a dark background, like Black Opal.
Similar to black opal except that the foreground color is very thin and sits on a brown ironstone base. These stones at times can come with interesting "hills" and "valleys" on the surface. (meaning that the surface is often, but not always, undulating) These stones are preferred by people who are more "progressive" in their jewelry tastes. Often boulder opal has ironstone inclusions in the foreground and all sorts of odd shapes which makes them a designers delight.
Formed in cavities and cracks of ironstone, usually from Queensland , Australia .
Boulder opal forms on a dark ironstone base (the host rock) and occurs as a thin uneven layer adhering to the ironstone. Because of the uneven layers, sometimes part of the ironstone is visible on the surface of the stone. Boulder opal is found in a wide range of colors including: green, blue, aqua, and pink. See opal varieties and opal description for more in depth discussions about this wonderful gemstone.
a seam of opal that is attached to its host matrix.
Boulder opal is a member of the opal family. It has a dark base surface with an exciting play of color. On Mohsâ€™ scale of hardness, boulder opal is 1.98-2.50. Its primary sources include Australia, Brazil, Guatemala, Honduras, Indonesia, Japan, Mexico, Russia, Nevada, and Idaho. (See Opal Facts.) (Note: Sources listed in order of primary and secondary deposits.)