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Opalized Clam shell (small clams fossilized with Opal). Handmade 14 kt. gold mountings custom fit to fossils.
With and with out diamond.

Higher resolution photos upon request

Australian Black Opal.

Handmade 14 kt. gold mountings custom fit to stones;
with and with out diamond.

Boulder Opal Pendants.

Hand made sterling silver mountings, made to fit each uniquely cut slab of boulder opal, no two alike in shape, design or opal pattern. silver acid etched.

Prices start at $100 and go up to $130 for the top center pendant.

Side view of the pendants.

The mounting are made from acid etched sterling silver sheet metal and fabricated to fit the stones.

What is "Boulder Opal"?

Boulder opal is found inside roundish shaped Ironstone rocks in areas of eastern Australia. The rocks are an iron-oxide-rich sand or mud stone. They likely started out life as mud balls, formed at the bottom of rivers by the moving water,

(like the way big snow balls for snow men are made).  You can see the layers of mud (like tree rings) in the cross section of the broken Boulder Opal specimen in the photo below.


When the river meanders, and starts a new course, the mud balls are left high and dry. When mud dries it shrinks and cracks.

If the mud balls are buried by wind blown sand and dirt, over time ( like 100,000 years) they turn to stone with the cracks still in place.

Opal is a sedimentary mineral deposit laid down by circulating ground water rich in silica.

The cracks in the "Ironstone" are filled over time ( like another 100,000 years) with the opal deposits.


Mud balls turned to stone are not unique to Australia. Below is a specimen of a mud ball from an ancient meander of the Volga River in Russia. Created by the currents of the river the mud balls grew by rolling on the bottom of the river. When left high and dry by the changing course of the river they dried out and cracked, see interior cracks in photos below. After this mud ball was turned to stone, it was later Pyritized.

Circulating ground water rich in Iron and Sulfur deposited the Pyrite (Iron sulfide) on the surfaces of the interior cracks, creating surfaces of tiny pyrite crystals.  These tiny crystal surfaces refract the light striking them, producing a surface of iridescent colors that change colors as your angle of view changes.