Which allotropes of sulfur exist naturally? I'm writing a paper on chemistry and I would like to know which allotropes of sulfur exist naturally. I've searched on the Internet but I haven't found anything about natural sulfur allotropes except this book(Ref. 1). Does anyone know the answer?
Reference

Steudel R., Eckert B. () Solid Sulfur Allotropes. In: Steudel R. (eds) Elemental Sulfur and Sulfur-Rich Compounds I. Topics in Current Chemistry, vol 230. Springer, Berlin, Heidelberg, DOI: doi.org/10.1007/b12110
The alpha and gamma form of cyclo-S8 are the only forms to occur naturally. Besides the reference provided in the question, you can also find more information in the wikipedia article of &quot;sulfur allotropes&quot;.