“embryonic planet that had a sulfur-rich core.”
Let it not be overlooked or forgotten “The Venusian atmosphere supports opaque clouds of sulfuric acid” so dense that earth based observations are obscured.
https://en.wikipedia.org/wiki/Atmosphere_of_Venus
[snip] Venus’ atmosphere contains about 96% carbon dioxide, 3% nitrogen, some argon and traces of water vapour (varying from 0.1 to 0.4%), oxygen, hydrogen chloride, hydrogen fluoride, hydrogen sulphide, sulphur dioxide, and carbon monoxide. [/snip]
https://www.eso.org/public/outreach/eduoff/vt-2004/Background/Infol2/EIS-D7_pf.html