A borate fluorescent powder and a preparing method thereof are provided. The formula of the borate fluorescent powder is Ba.sub.2-nSr.sub.nLu.sub.5-x-y-m-zL.sub.mCe.sub.xTb.sub.yEu.sub.zB.sub.5O.sub.17. L is one or any combination of the elements Gd, La, and Sc. Ranges of x, y, z, m, and n are respectively 0<x≤0.6, 0<y≤3, 0<z≤0.4, 0≤m≤1, and 0≤n≤0.5. The borate fluorescent powder provided has a stable crystalline phase, high luminous efficiency, and decent thermal stability, and can be applied to ultraviolet LEDs or near-ultraviolet LEDs to construct white LEDs.

A borate fluorescent powder and a preparing method thereof are provided. The formula of the borate fluorescent powder is Ba.sub.2-nSr.sub.nLu.sub.5-x-y-m-zL.sub.mCe.sub.xTb.sub.yEu.sub.zB.sub.5O.sub.17. L is one or any combination of the elements Gd, La, and Sc. Ranges of x, y, z, m, and n are respectively 0<x≤0.6, 0<y≤3, 0<z≤0.4, 0≤m≤1, and 0≤n≤0.5. The borate fluorescent powder provided has a stable crystalline phase, high luminous efficiency, and decent thermal stability, and can be applied to ultraviolet LEDs or near-ultraviolet LEDs to construct white LEDs.

The invention relates to faceted gemstones based on a luminescent glass composition that contains particular oxides of rare earth metals and thus enables the faceted gemstones to be identified, and to a process for identifying the gemstones.

The invention relates to faceted gemstones based on a luminescent glass composition that contains particular oxides of rare earth metals and thus enables the faceted gemstones to be identified, and to a process for identifying the gemstones.