This is an exceptionally rare and scientifically significant natural specimen—combining two phenomena that almost never occur together: fossilised dinosaur bone and precious opal formation.

The fossils originate from the Winton Opal Fields, one of the very few places on Earth where opalised dinosaur remains have been discovered. During the Cretaceous Period, this region supported large herbivorous dinosaurs, including sauropods. Under extremely specific geochemical conditions, silica-rich groundwater gradually replaced organic bone material, forming opal instead of standard fossilisation—an event considered extraordinarily uncommon in palaeontology.

Opalised dinosaur fossils are already rare on a global scale, but vertebral elements from a sauropod—particularly preserved across multiple matching pieces—are rarer again. The presence of “Type 3” solid opal with blue-green fire further elevates its uniqueness, as this indicates high-quality gem-grade opal replacing original bone structure rather than merely coating or filling voids.

Its provenance strengthens its importance:

Documented and studied by Dr Andrew Rozefelds and museum colleagues

Referenced in the Queensland Museum’s 2026 guide (In Search of Ancient Queensland)

Originating from a historic private find over 25 years ago, with long-term family custody

Recently authenticated by a professional gemstone laboratory (GSL)

From a rarity standpoint, pieces like this sit at the intersection of:

Museum-grade palaeontological specimens

High-value gemstone material

Documented provenance and scientific validation

Very few specimens worldwide meet all three criteria simultaneously.

In practical terms: this is not just a collectible—it is a crossover artefact of natural history and gemmology that would be considered rare even within major institutional collections.

The solid opal specimen type 3 is 93.3 mm length 49.3 mm width and 51.8 mm depth and weighs 772 cts

The matching opalized opal in blue green fire is 40 mm length 24.2 mm wide and12.6 mm depth weighs 70.45 cts

Certificate and Ancient Queensland book included