Univ. of Hong Kong Scientists Develop 'Hunter Drone' That Can Seek Out Gem Deposits

A pair of scientists from The University of Hong Kong have developed an autonomous "hunter drone" that can survey wide landscapes and identify valuable gemstone targets using a scanning laser. The drone flies at night and emits a powerful beam that causes fluorescent items on the surface of the ground to glow.

The drone was originally intended to look for fossil bones, hence its name "Laser Raptor," but the scientists quickly realized that the drone's capability was far more reaching. Other florescent targets could include rare minerals, such as ruby, kunzite, opal and diamond, to name a few.

Of the diamonds submitted to the Gemological Institute of America for grading over the past decade, approximately 25% to 35% exhibit some degree of fluorescence, a factor that — for the overwhelming majority of diamonds— has no widely noticeable effect on appearance.

In a paper published in the journal Methods in Ecology and Evolution, HKU Research Assistant Professor Dr. Michael Pittman and his colleague Thomas G. Kaye of the Foundation for Scientific Advancement described a prototype drone that was programmed to look for fossils at night in the badlands of Arizona and Wyoming.

At first, the Laser Raptor flew rapidly to search locations using its on-board navigation, and then descended and maintained an altitude of 4 meters above ground so it could "mow the lawn" in search of glowing targets as small as a thumbnail.

After each “mission” was complete, a video of the laser scan was processed to find hot spots that were investigated in more detail the next day, leading to the recovery of new fossil specimens.

They explained that the application of laser-stimulated fluorescence (LSF) to an aerial system is possible because of the laser's ability to project over great distances with little loss in power.

Pittman and Kaye reported that they are now working to develop LSF applications for the study of geologic landscapes beyond Earth.

Credits: Images by Thomas G. Kaye & Michael Pittman / The University of Hong Kong.

Artisanal Miner Discovers Two Tanzanite Crystals Weighing a Combined 75,000 Carats

An artisanal miner in Tanzania struck it rich last week when he sold two enormous tanzanite crystals for $3.4 million.

Saniniu Laizer had discovered the crystals — one weighing 9.2kg (46,000 carats) and the other 5.8kg (29,000 carats) — in Tanzania's Manyara region, not far from the country's Merelani mining site.

The two rough gems are believed to be the largest tanzanites ever found in Tanzania. The previous record holder weighed 3.3kg.

In a highly promoted ceremony on Wednesday, the 52-year-old Laizer revealed his finds to the international press.

"There will be a big party tomorrow," he told the BBC.

Laizer also promised to invest his windfall in the local community of Simanjiro.

"I want to build a shopping mall and a school," he said. "I want to build this school near my home. There are many poor people around here who can't afford to take their children to school."

Calling into the celebration by phone, Tanzanian President John Magufuli commented, "This is the benefit of small-scale miners and this proves that Tanzania is rich."

When Magufuli came into power five years ago, he promised to safeguard the nation's mining sector and ordered the military to build a wall surrounding a Manyara mining site.

Tanzanite is said to be rarer than diamonds by a factor of 1,000 times due the fact that this unique and beautiful variety of the mineral zoisite is mined in only one location on earth. The area measures 2km wide by 4km long and the remaining lifespan of the mine is less than 30 years. Tanzanite’s color is an intoxicating mix of blue and purple, unlike any other gemstone.

Artisanal miners like Laizer are permitted to work outside the confines of the Manyara mining site as long as they carry a government-issued license. In 2019, Tanzania established trading centers to allow these miners — most of whom work by hand — to sell their gems to the government.

In 2002, the American Gem Trade Association added tanzanite to the jewelry industry’s official birthstone list. Tanzanite joined turquoise and zircon as the official birthstones for December.

Credit: Image © Tanzania Ministry of Minerals.