FYI: Sister metals of platinum.

The Sister Metals of Platinum
Platinum is rarely found alone. It is almost always mixed with other similar and valuable metals known as the platinum group metals (PGMs): palladium, rhodium, ruthenium, iridium, and osmium.
Where is Platinum Found?
• Platinum can be found in placer deposits (like rivers) with gold, silver, and black sand.
• It is also found in sulfide ores of nickel and copper, such as those in Canada.
• Often, platinum is recovered as a by-product during the extraction of other metals like gold, silver, or copper.
• It can also be recycled from scrap – such as old jewelry, industrial waste, or electronic components.
How Do We Know If There’s Platinum in Soil?
• When gold prospectors pan black sand, they sometimes find heavy gray grains, which could be platinum alloys.
How Is Platinum Extracted and Refined?
In this lesson, we will focus on:
• Extracting platinum from scrap or chemical residues (sludge or mud).
• Refining platinum from alloys (mixed with other metals like silver or copper).
• Separating platinum found with free gold through panning or sluicing.
Note: It’s very rare to find a pure platinum mine or rich deposits of a rare platinum mineral called sperrylite (PtAs₂), so we won’t cover that method.
Which Platinum Group Metals Matter Most?
The most important and useful PGMs for you are:
• Platinum
• Palladium
• Iridium
The other three (rhodium, ruthenium, and osmium) are usually found in very small amounts. So it’s better to sell the remaining mud or residues that contain them to a professional refinery instead of trying to refine them yourself.
A Simple Chemistry Note:
• Platinum does not dissolve in regular acids, alkaline solutions, or cyanide.
• It does dissolve in aqua regia (a mix of nitric and hydrochloric acid).
• When dissolved, it forms platinum chloride, the most common and useful platinum salt.