Scientists have finally managed to uncover the secret behind natural stones that can glow in the dark and change color.
Nationalgeographic.co.id— In general, materials that ‘glow in the dark’ are often used by people who are traveling on cruise ships or airplanes, where these materials serve as aids for emergency exit signs that can turn on by themselves.
The materials used today are actually synthetic materials. persistent luminescence (persistent luminescence/PeL) in the form of green light can be obtained from divalent europium doped to synthetic strontium aluminate. However, scientists at the University of Turku have managed to find a natural mineral glow that produces white glow when in the dark.
There are several natural minerals that can produce glow, one of which is hackmanite. How do scientists identify it?
Hackmanite It is a rare member of the Sodalite sulfur chloric sodium aluminum silicate family. This material crystallizes in mass, cubic and octahedral formations. It is one of the few minerals that tenebrescence (can change color when exposed to sunlight), as well as UV reflective.
This material can also be seen in a variety of colors such as gray, green, yellow, purple, pink, and blue, but is most commonly found in dusty white. Hackmanite It was first discovered in Greenland by LH Borgstroem in 1901.
Borgstroem gave the mineral its name after the famous Finnish geologist Victor Axel Hackman. Important deposit hackmanite located in Afghanistan, Myanmar, Canada, Pakistan, Norway and Russia. Even so, not all hackmanite can glow in the dark.
As reported by Techexplorist.com, Isabella Norrbo, a Postdoctoral researcher who took part in the study said, “We have done a lot of research with synthetic hackmanite and have been able to develop a material with a clear glow for much longer than natural hackmanite.
He added, “However, the conditions affecting the luminescence are unclear so far.”
Isabella’s research on hackmanite has been published in the journal ACS Publications on September 25, 2020 entitled ‘Hackmanite—The Natural Glow-in-the-Dark Material’. The research was carried out as a collaboration between scientists and international teams from various fields.
According to Sami Vuori, a doctoral candidate who also participated in the research, “Nature has extensive experience in optimizing minerals, which is why we used natural hackmanite to study the glow effect.”
“Through this extensive collaboration, we were able to conclude that the most central elements behind the natural glow of hackmanite are sulfur, titanium, potassium and iron, as well as the correct balance of concentrations,” said Mika Lastusaari. He is a lecturer and concurrently head of photonics research in the Inorganic Materials Chemistry research group at the University of Turku.
Titanium makes hackmanite shine
To support this study, which was funded by Business Finland, French National Research Academy ANR, Pôle de Compétitivité from France, São Paulo Research Foundation FAPESP, and Ghent University, scientists linked experimental data and computational data. Which in the end they found that titanium was shining in the core of hackmanite, and the remnants associated with the transfer of electrons in the conduction band.
Hackmenite (Afghan variety) exhibits photochromism when irradiated with ultraviolet light.
A gemstone made from natural hackmanite.
In this regard Lastusaari explains, “With these results, we obtained valuable information about the conditions that affect hackmanite remnants. Although nature, in this respect, has not been able to form materials with fluorescents as effectively as synthetic materials, nature has helped significantly in the development of increasingly effective fluorescent materials.”
“Optimizing natural materials gives us the possibility to discover how hackmanite produces light most effectively,” said another researcher, Cecilia Agamah.
Natural minerals often contain complex compositions and differ somewhat in composition depending on the conditions under which they are formed. This natural mineral is very helpful for researchers in developing fluorescent materials that can glow effectively in the dark.