Age of the Earth Creation/evolution Paleontology

Opalised fossils or pseudofossils

“Opal is a spectacular gemstone. It is also a dazzling key to Australia’s mysterious past, because buried in the Australian opal fields are fossils of dinosaurs and other strange creatures that lived 110 million years ago, in Early Cretaceous times.”

Figure 1: Belemnites were cephalopods. The ammonites are another extinct cephalopod. Living cephalopods include octopuses, cuttlefish, squid and nautiloids.

This is the opening sentence on the website National Opal Collection. The Early Cretaceous period is alleged to be from 146 million to 100 million years ago.

Fossils are the remains or impressions of living organisms preserved in sedimentary rocks. When the fossils are opalised they become literally gemstones. Teeth, bones, shells and pinecones have been found fossilized and turned to solid opal. Australia is a ready source of opals.Coober Pedy and Lightning Ridge are well known for their mines. You will find opals for sale in most central tourist areas of Australian cities.

But how does anything become opalised? It’s not magic. Most people think it takes millions of years to occur.

“And surprising as it may seem, the ingredients of opal are commonplace stuff.  Water in the ground carrying dissolved silica (similar to the glass in windows) is said to have seeped through beds of sand and grit, where the silica particles are deposited in cracks.  As the water subsequently evaporated, the silica particles became ‘cemented’ together to form the opal.  Light bending around the silica produces the variety of glowing colours.”3

Australia is the only country where opalised animal fossils are found.4

“Perhaps the most famous example in recent years is ‘Eric’ the pliosaur (a marine reptile), which was the subject of high-profile public fund-raising by The Australian Museum in Sydney in order to purchase these opalized bones from the Coober Pedy miner who found them in 1987.  ‘Eric’ is said to be about 100 million years old.  No wonder then, in most people’s minds, because of these claimed time scales, and because of the almost universal perception/indoctrination that geological processes are almost always slow and gradual, opals ‘must’ have taken a long time to form in the ground.”3

Opalised fossils are rare and precious… .” The National Opal Collection website continues “… even more so because in Australia, it is rare to find fossils of any kind from the time of the dinosaurs.”1 But opals have been made in a matter of weeks with the right chemical conditions and examined by experts and found to have no distinguishable differences from the real opals found at Lightning Ridge.3 Hence, there is no reason to suppose they are evidence for millions of years of deep time in the fossils from that alleged age of dinosaurs.

Opalised Belemnite fossil

While walking past an opal shop in Adelaide (South Australia) a few weeks ago I noticed, and photographed, this opalised Belemnite fossil (Fig. 1), and a few other shown below. Notice its shape is very much like a modern squid. This part of the specimen is the most commonly preserved part of the animal, the reduced shell, which has become an internal support, like the pen of a squid, or a cuttlefish skeleton. It is beautifully opalised. And now that it is known opalisation can occur over a brief period of time, not millions of years, such a find presents itself, to one thinking biblically, as evidence of the past global catastrophe that buried and resulted in the fossilization of many marine creatures. 95% of all fossils are of marine origin.

Rare opalised ‘pineapple’

Figure 2: Rare White Cliffs opalised ‘pineapple’

In the opal shop this rare opalised ‘pineapple’ particularly caught my attention (Fig. 2). They look like pineapples but they are not; they are opalised pseudo-pineapples. They are pseudofossils. That means they are not a fossil nor were they once pineapples. They only have the appearance of a pineapple.

They have a crystal-like shape but they are not crystals. Since opal is an amorphous mineral, meaning it is not crystalline, it cannot have a crystalline form. These opal ‘pineapples’ are pseudomorphs, which occur when one mineral replaces another making a cast of the original mineral.

“An opal pineapple is an opal pseudomorph, the cast, after a radical cluster of pyramidally terminated crystal, which superficially gives the specimen some similarity to that of the fruit. The original mineral (in Fig. 2) is thought to be glauberite, a mixture of calcium sodium sulphate.”5

In this case opal has replaced the original mineral which may have been glauberite or ikaite, which was first replaced by calcite and then opalised. But the ikaite only crystallises in near freezing conditions. The secular evolutionary explanation is that these opalised ‘pineapples’ had their origin in a past ice age.

But the global conditions after the world-wide flood in Noah’s day are the only conditions that can cause a global ice age to occur. That means there were present both warm oceans, hence high evaporation, and cold continents, which caused high precipitation onto the land masses. That combination guaranteed an ice age to follow, which is estimated to have lasted for 500 to 700 years after the flood waters receded from the land masses. Coupling that biblical historical time frame with the fact that we now know opalisation occurs quickly, under the right conditions, you have both near freezing weather for the growth of the calcite in the ‘pineapple’ and sufficient time since the Ice Age (of about 4000 years) for its subsequent opalisation. No millions of years needed there.

Opalised Yowah Nut

Yowah is a small town in the ‘outback’ of western Queensland, Australia, located 938 kilometres (583 miles) west of the state capital, Brisbane. As of the 2006 census Yowah had a population of 142. No one would blame you if you said you have never heard of Yowah. I certainly hadn’t until I walked into that opal shop.

Yowah town is apparently known for its opal mining and the opal fields around the town. It is particularly well known for the “Yowah Nut,” (Fig. 3) a type of opal distinctive to that region.

Figure 3: A rare opalised “Yowah Nut”.
Figure 3: A rare opalised “Yowah Nut”.

These “Yowah Nuts” occur in Southern Queensland where the opal minerals infill the central cavity in ironstone concretions. There is no nut involved nor was there ever any living organism.

Opals are nothing more than hydrous silicon dioxide, meaning essentially ‘wet sand.’ It is not crystalline like other gemstones but an amorphous silicate.2 But it is their beauty that sets them apart. The rich play of colours in some opals gives them their unsurpassed splendor and mystique, making opal one of the most fascinating gemstones.

The fact that we find many opalised fossils gives us some information about their origins. Opal mineral can contain up to 20% water. So where do you find a connection between dead creatures being fossilized and a lot of water? And when would the weather be where there were freezing temperatures, cold enough to produce calcite crystals that are later replaced by amorphous opal mineral? These circumstance were present in and after the global flood in Noah’s day, which was followed by the one and only Ice Age. So these beautiful gemstones speak of a time of upheaval in the world, yet most of those who wear them, in rings and necklaces, have no idea of their origin.

 “The waters are hid as with a stone, and the face of the deep is frozen.” (Job 38:30)


  1. National Opal Collection, accessed February 24, 2016.
  2. The Mineral Opal,, accessed February 24, 2016.
  3. A. Snelling, Creating opals: Opals in months—not millions of years!, Creation 17(1):14–17, December 1994.
  4. Umoonasaurus demoscyllus, Australian Museum, accessed February 24, 2016.
  5. White Cliffs Opal, accessed February 24, 2016.

By John Gideon Hartnett

Dr John G. Hartnett is an Australian physicist and cosmologist, and a Christian with a biblical creationist worldview. He received a B.Sc. (Hons) and Ph.D. (with distinction) in Physics from The University of Western Australia, W.A., Australia. He was an Australian Research Council (ARC) Discovery Outstanding Researcher Award (DORA) fellow at the University of Adelaide, with rank of Associate Professor. Now he is retired. He has published more than 200 papers in scientific journals, book chapters and conference proceedings.