Dictionarium polygraphicum. Dust. Brass dust. Silver dust. Gold dust. Tin dust or powder. Copper dust.

Dictionarium Polygraphicum:
Or, The Whole Body of Arts Regularly Digested.
Vol I.
London: Printed for C. Hitch and C. Davis in Pater-noster Row, and S. Austen in St. Paul's Church Yard. MDCCXXXV.
1735
BRASS DUST.
This is commonly call'd gold dust; the best (which comes from Germany) is that which is the brightest and most gold like colour, which is to be perceiv'd by taking a little of it between your finger and thumb, and rubbing them together; if it be good, it will be of a bright, rich, golden lustre; if bad, will be of a dull, clayish colour.
The coarser sort works well, with gold size; but not with gum-water. It is of different prices, according to the goodness; the best is worth twelve or fourteen shillings the ounce, when at the same time some other sorts are not worth above four or five shillings the ounce. The middle sort, which is worth eight or nine shillings the ounce, will work well.

Silver DUST.

The best of this comes from beyond sea, having a lively bright lustre, like that of polish'd, or new coined silver, which is to be perceiv'd by rubbing it between your finger and thumb; whereas the worser sort (which is made in England) is dull, dead, and heavy, more fit for a colour than a metal. The difference is easily perceived by comparing them together.
The best is worth sixteen shillings the ounce; the other counterfeit is not valuable.

Green GOLD DUST is an adulterated or mixt metal, casting a kind of dead, greenish colour, and is worth about six shillings the ounce.
This, as also the following, are us'd in garments, flowers, houses, and the like, making the work more beautiful and sur prizing.

Sullied or dirty coloured GOLD DUST is also a kind of adulterated metal, bearing some resemblance to drossy gold. The price is six shillings the ounce, and is us'd for the same occasions as the former.

Tin DUST or POWDER is made of block tin ground to powder, and is of a dull, dark, but silverish colour; it is us’d in rocks, &c. and is sold for six shillings an ounce.

Natural copper DUST is made of copper ground, without mixture to dust. This is of the true natural colour of copper, and is sold for six or seven shillings the ounce.

Artificial copper DUST.
This exceeds the natural, and is more deep or red; but very clear, and of a bright shining colour, and shews how far art can out-do nature. It is sold for about ten shillings the ounce.

Adulterated copper DUST is of a thick, heavy, dull, metal lick colour, and commonly us’d to work other metals on; for being laid as a ground, you may hatch or heighten with bright gold, or other shining metal, and is sold for about six shillings an Ounce.