Diamond or zirconia? Apart from the price, it can be hard to tell these two gems apart.
Zirconia is a mineral with a crystal structure made from the elements zirconium and oxygen. It looks pretty like diamond, but is only worth a fraction of the value.
Sapphire beads in a Jaipur workshop.
Sapphires and rubies are both crystals of the mineral corundum - but with different impurities to create blue and red hues. Australian sapphires are renowned for being inky blue.
Many scientists believe it is impossible to ignore the human impact on the planet when defining the geological age we live in today.
When it comes to the geological record, airbrushing out humans' impact on the environment makes little sense.
What’s going on 150 kilometers below the Earth’s surface?
Good Free Photos
A new array of seismometers provides a glimpse of what's happening deep beneath this geologic fault. New data help explain why the north and south of the region are more seismically active than the middle.
The first three Natural History Museum painites – including one in its natural state with rubies that had been sitting in their collection for years. It had initially been misidentified as the much less valuable tourmaline.
© The Trustees of the Natural History Museum, London
What makes a stone a gem? It boils down to a few key qualities: beauty and durability. But opal, the national gemstone of Australia, is an anomaly - it's soft.
Some explosive volcanoes can send ash high up into the sky and it can travel around the world over different countries.
When magma rises towards the surface gas bubbles start to form. Whether or not they can escape as the magma is rising affects how explosive the eruption will be.
It’s been 50 years since the find of burnt bones in ancient soil, eroded from deep in shoreline dune in NSW.
It's been half a century since Jim Bowler discovered Mungo Lady which changed the course of Australian history. But now he says the find has fallen off the national radar, leaving a legacy of shame.
Where all the water in the ocean came from is a very good question. Scientists have been wondering about it for a long time.
The Big Bang created a cloud of dust and rocks that included a lot of rocks that were made of ice, like giant snowballs. That's where some of the water came from.
From vineyard to glass.
Wine drinkers are taking notes from the land now too, but it may not be entirely useful.
Long’s Peak framed by rock outcrop, Rocky Mountain National Park, Colorado.
Scientists have long thought most nitrogen in Earth's ecosystems comes from the air, but new research shows it also is released as rocks weather. This could boost plant growth and help sequester carbon – but not fast enough to avert climate change, as some pundits have claimed.
In the field studying the rock association in the Doolena Gap greenstone belt, 30 km north of Marble bar in the Pilbara region of Western Australia.
The remote Pilbara region of Western Australian formed many billions of years ago when the Earth was much hotter and the crust softer than it is today.
Tides are the largest they have been for 250m years.
Gosses Bluff impact crater in the Northern Territory.
NASA’s Earth Observatory
Large asteroids have hit Australia over many millions of years and the evidence is in the landscape, if you know where to look.
Google Earth. Data SIO, NOAA, US Navy, NGA, GEBCO
East Africa Rift is undergoing a process that will see the Horn of Africa split from the rest of the continent.
Through abstraction, the underlying essence of a mathematical concept can be extracted.
An artist’s rendition of the InSight lander - which will collect data on what’s inside the planet Mars.
The InSight Lander mission to Mars is preparing for launch in May 2018. But there are seven (or eight) other planets to explore: why have we such a hang up on Mars?
Seismic shockwaves after a meteorite’s collision could affect systems all over the planet.
Research suggests a new threat to life on Earth from the meteorite's crash: Via seismic waves, the impact triggered massive undersea eruptions, as big as any ever seen in our planet's history.
Rising waters: Paris, January 29, 2018.
It was the Seine’s rise and fall, in response to heavy rain, that inspired our current understanding of river systems.
A drying climate caused a mass extinction among plants, but paved the way for the ancestors of modern reptiles, mammals, and birds.
The extinction of dinosaurs is one of the many periods of mass extinctions on earth.
Scientists believe since 2010 we have entered the sixth period of mass extinction. CO2 emissions will change the lives of plants and animals in the next three to four decades.