I was really surpised to see that strontium is apparently more common than sulfur in the earth's crust, since it occurs in what I thought were pretty rare minerals.
Sulfur which seems to be everywhere such as in volcanoes, in the atmosphere as sulfur dioxide, in coal deposits, and is even found elementally in large lenses.
Sulfur seems to be ubiquitous. For example, fool's gold, iron pyrite is iron sulfide and it can be found in practically any stream bed. I would be hard pressed to find strontium in my local stream beds. And, of course, this sulfide is only one of many commonly sulfides.
Is strontium really more common than sulfur? It seems implausible. What is the basis for this claim?