What kind of rock is this


Sr. Member
Jul 23, 2012
Was found in woods in nyc IMG_0757.jpg
IMG_0756.jpg IMG_0755.jpg


Hero Member
Jul 27, 2018
Primary Interest:
All Treasure Hunting
Looks like mudstone with embedded pebbles. I found some that resemble that in eastern Virginia near the Potomac river last year.
Upvote 0


Gold Member
Apr 24, 2010
Upper Canada 🇨🇦
🥇 Banner finds
🏆 Honorable Mentions:
Detector(s) used
XP Deus, Lesche Piranha 35 Shovel & 'Garrett Carrot'
Primary Interest:
Relic Hunting
Without any background information or knowing the environmental conditions on where you found this piece, all we can do is guess? :dontknow:
My first thought was iron ore slag. :icon_scratch:

"Slag is the glass-like by-product left over after a desired metal has been separated from its raw ore. Slag is usually a mixture of metal oxides and silicon dioxide. However, slags can contain metal sulfides and elemental metals. While slags are generally used to remove waste in metal smelting, they can also serve other purposes, such as assisting in the temperature control of the smelting, and minimizing any re-oxidation of the final liquid metal product before the molten metal is removed from the furnace and used to make solid metal. In some smelting processes, such as ilmenite smelting to produce titanium dioxide, the slag is the valuable product instead of the metal.

Basic slag is a co-product of steel-making and is typically produced either through the blast furnace - oxygen converter route or the electric arc furnace - ladle furnace route. To flux the silica produced during steel-making, limestone and/or dolomite are added, as well as other types of slag conditioners such as calcium aluminate or fluorspar. The major components of these slags therefore include the oxides of calcium, magnesium, silicon, iron, and aluminum, with lesser amounts of manganese, phosphorus, and others depending on the specifics of the raw materials used."


  • 1280px-Slag_from_iron_ore_melting.jpg
    256.9 KB · Views: 23
Upvote 0

Top Member Reactions

Users who are viewing this thread