Some of the microfractures may also represent desiccation cracks in thin coatings of potassium alum observed by SEM.
Nevertheless, the common corrosion of feldspar grains and clay minerals in the matrix could have provided free silica and alumina for the secondary salts, notably potassium alum.
When roselle extract mordanted with potassium alum, alkalinized with ammonia was applied on the testicular section and counterstained with eosin (Fig.
5) on the section of the testis showed a good nuclear/ cytoplasmic differentiation as observed with the potassium alum counterpart, but in this case the connective tissues were more clearly demonstrated.
Other fumarolic minerals present include potassium alum
, as sharp, complex colorless crystals and as colorless to white "rams horn" growths, often with millimeter-sized gemmy sulfur crystals sprinkled on them, proving that the sulfur was deposited later (and presumably at an even lower temperature) than the alum.
, jarosite) in evaporites derived from its weathering.