While looking at the strontianite page, [
www.mindat.org], I noticed that strontianite is rightfully listed as a member of the "aragonite group", yet aragonite is not listed in the "Related Minerals - Hey's Index Grouping" list of minerals, although other members of the aragonite group are - this is not an uncommon problem, but may require some work to address as all mineral entries would need to be inspected?