Japanese Scientists Invent "Unbreakable" Glass

The official journal title of this article is "High Elastic Moduli of a 54Al₂O₃-46Ta₂O₅ Glass Fabricated via Containerless Processing"

Yeah, Containerless Processing.

Because that's a thing now apparently.

The IFLScience article summarizing the research does a really nice job explaining previous challenges in production of alumina/tantala (Ta₂O₅) glasses was that the alumina would crystallize out of the mixture against the edges of the container long before any substantially homogeneous mixture could form.

The solution, obviously, was to produce the glass without a container...

Glasses were fabricated using an aerodynamic levitation furnace described elsewhere. High-purity (99.99%) α-Al₂O₃ and Ta₂O₅ powders were mixed stoichiometrically with the chemical composition 54Al₂O₃-46Ta₂O₅, pelletized using a hydrostatic press, and annealed at 1050 °C for 12 h in air. Pieces obtained from the crushed pellets were levitated in an oxygen gas flow and melted using two CO₂ lasers at approximately 2000 °C. The melt was rapidly solidified by shutting off the lasers at a cooling rate of approximately 300 °C/s in order to obtain fully vitrified samples. The obtained spherical glasses (2 mm in diameter) were colorless and transparent.

...because that's just the easiest thing to do.