The gambling currency, Nethershard is known for most players in Patch 7.2, which has a chance to get the legendary items and ilvl925 raid gears.
While in Patch 7.3, Nethershard will be replaced by Veiled Argunite.

You can purchase Relinquished tokens with Veiled Argunite from Thaumaturge Vashreen. He's now located in the basement of the Vindicaar. The original gears ilvl is 910 and there is a chance to open Warforged or Titanforged Gears. What matters is that you can purchase different kinds of artifact relics directly. This change is really amazing!

How to acquire Veiled Argunite?
1. The Weekly Argus Invasion quest Invasion Point Offensive.
2. The new dungeon quest Seat of the Triumvirate: The Crest of Knowledge.
3. The Weekly quest to kill rares on Argus: Fuel of a Doomed World: Collect 50 Pristine Argunite from Invasion Points, Rare encounters, or treasure chests on Argus.
4. Defeating rare spawns or opening treasure chests.
5. As a reward from Argus World Quests.
6. At Revered with Argussian Reach, you can purchase the enchants shoulders with the Steadfast enchantment and you have a chance to obtain the Veiled Argunite Clusters from the enemies corpses.
These are many ways to gain Veiled Argunite, and perhaps there are other ways to get it. But, the main ways to get Veiled Argunite is to farm the quests or the Weekly Quest at present.
Hope all we have a good luck to obtain your favorite gears!