White & yellow stone-like objects in the soil of potted plan

Question

What are these small stone-like objects in a potted plant? They are present in multiple plants and I was wondering if this is a pest or an illness, or nothing to worry about.

Answer 1

This is most likely to be perlite or small stones. Perlite is

an amorphous volcanic glass that has a relatively high water content, typically formed by the hydration of obsidian. It occurs naturally and has the unusual property of greatly expanding when heated sufficiently.

You can verify this by picking up a piece and trying to crush it. If it can be crushed into small white dust like particles it is perlite.

Small stones are sometimes seen in soil mixes for cacti and succulents or in home mixes of topsoil.

None of these are harmful to plants.