Hi pomona
I live in Dhofar which is called the land of frankincense. its climate promoted the highest quality frankincense among the other producers such as Somalia, yemen, and Ethiopia. In fact Somalians, Yemenies and Ethiopians are now got licenses in Oman to harvest frankincense. they know the difference so don't be intimedated by any location as most frankincense have similar healing powers.
you can get Somalian, yemeni, ethiopian, or Dhofari. just make sure you don't buy the oil. because it has become a dirty trade where they use chemicals to disolve frankincense.
in worst cases they will heat it with an oderless oil till it disolves. so you will never get 100% or even 60% pure frankincese oil. in fact there is no such thing.
just buy raw frankincense and put one or two peices in water for more than 24 hours. let it souk and remove any hard parts
you only need that much to digest or treat your skin.
you can trust my words as my brother is knowledgeable in this field.
do you also know that frankincense kills cancer cells? yes in deed, there was a study done in my city and published by University of Leicester in the UK.
check it out here http://drericz.com/frankincense-oil-kills-cancer-and-boosts-immunity/
you may also check this website which contains information about frankincense and sells raw Dhofari frankincense
http://positive-energy-luban.com/
regards,