TUNGSTEN (W) TEST

There are four main ores in the Tungsten (W) Family: Wolframite - Ferberite - Hubnerite each hosts about 75 percent Tungsten Trioxide and Scheelite which contains 80 percent Tungsten Trioxide. Wolframite-Ferberite-Hubnerite all are of dark colored ores, and resemble common black iron ores or rocks, whereas Scheelite is just the opposite and usually appears as white or yellow resembling the average quartz, calcite and barite, or, perhaps when associated with copper ores will appear to be a green color.

As a test with a porcelain evaporating dish with Hydrochloric Acid (HC1) and with Tin (SN); this mixture is named Stannous Chloride solution. Place the powdered suspected ore, the size of 2 grains of rice onto the porcelain evaporating dish and add 2cc of strong Hydrochloric Acid (HC1), then add to this a small piece of pure metallic tin or tinfoil. (Note; 1cc equals about 20 drops from an eye dropper.)

Place this evaporating dish over the lamp flame until the solution changes color, then allow it a second or two longer to remain on the flame; but do not boil it until dry: NO! The solution will usually turn yellow, brown or red, but upon boiling with the metallic tin the solution will always turn colorless before the blue of Tungsten appears; therefore, always boil until the solution appears clear, then a couple of seconds longer with the test made.

Perhaps in some tests it may be necessary to add more acid and tin to assist in bringing about a color change; be alert to this.

NOTE: Sample ores should always be selected for powdering that appear with brown or black particles in suspected Tungsten ores, and for Scheelite the suspected ores should contain light colored particles.

Delos Toole Copyright 2000.