A Unique Diamond With Another Diamond Moving Freely Inside

  • An unusual diamond has been discovered in Siberia. 
  • It’s a diamond inside another diamond: the internal diamond is completely loose and freely rattles around the cavity inside the other diamond. 
  • Such crystal has never been found in the history of global diamond mining.

While the Earth is believed to be 4.5 billion years old, the oldest diamonds are considered to be crystallized nearly 3.3 billion years ago. These crystals are formed 90-122 miles beneath the surface of the Earth under extreme heat and pressure.

After centuries of scientific advancements, diamond mining has now become an incredibly skilled process. Today, we have different methods to extract these precious gems without risks of damaging them. In 2018, 147 million carats of diamonds were estimated to have been produced from mines across the world.

Recently, a Russian mining company ALROSA discovered an unusual diamond in the Sakha Republic of Siberia. It is named ‘Matryoshka Diamond’ after Russia’s iconic stacking dolls.

They found a diamond inside another diamond. The internal diamond is completely loose and freely rattles around the cavity inside the other diamond. This the first of its kind: no such diamond has ever been found in the history of global diamond mining.


The diamond has a maximum dimension of 4.8 x 4.9 x 2.8 millimeters and weighs 0.124 grams (0.62 carats). The internal cavity volume is about 6 cubic millimeters while the internal diamond volume is 1.6 cubic millimeters. The inner, tabular-shaped crystal has a dimension of 1.9×2.1×0.6 millimeters and weighs only 0.004 grams (0.02 carats).

Source: ALROSA

Unlike most natural diamonds that have ages between 1 billion and 3.5 billion years, the matryoshka diamond is about 800 million years old.

Credit: ALROSA

Amazed by its complex structure, the mining company handed it over to the ALROSA’s Research and Development Geological Enterprise for further analysis. They studied the diamond using different techniques, including X-ray microtomography, Raman and infrared spectroscopies.

Since this type of diamond has never been observed before, scientists aren’t sure how it formed in such strange scenarios. However, they do believe that the inner crystal was formed first and then the external one came into existence during the subsequent stages of growth.

X-ray view 

Many diamonds consist of other flecks of minerals and tiny crystals, which make the diamond impure. In this case, however, the inner material is actually another diamond, not an impurity.

But how the air gap between the outer and inner crystal was formed? They have two main theories:

  1. The diamond was captured by a mantle mineral during its growth and then dissolved in the surface of the Earth.
  2. Because of the superfast growth of the diamond, a layer of porous polycrystalline diamond material formed inside it, and later it was dissolved by more aggressive mantle processes. And because of the existence of the dissolved region, one crystal began to move freely inside another.

Read: Physicists Achieve Quantum Teleportation Inside A Diamond

Considering the fact that nature doesn’t like emptiness, this diamond is really an unusual creation of nature. Typically, some minerals replace others without forming any cavity.

Written by
Varun Kumar

I am a professional technology and business research analyst with more than a decade of experience in the field. My main areas of expertise include software technologies, business strategies, competitive analysis, and staying up-to-date with market trends.

I hold a Master's degree in computer science from GGSIPU University. If you'd like to learn more about my latest projects and insights, please don't hesitate to reach out to me via email at [email protected].

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