Frankincense researchers, exporters and botanists disagree on whether Boswellia carterii and Boswellia sacra are identical varieties. Contacts in Somalia have told me that there are three different carterii types in Somalia, but these could also be sacra trees. For many, Boswellia sacra is merely a synonym for Boswellia carterii. And indeed, the resins of the two trees are similar. However, I myself never considered the two siblings to be the same species. Recent research also indicates that they are not, in fact, the same tree.

Boswellia sacra from Oman is considered the purest frankincense in the world and is the most sought-after (and most expensive) of all the varieties. When speaking about this prized gem, we can’t gloss over the special region in Oman where it grows: the Dhofar area. Although there are several harvesting areas, the best quality comes from the Qara mountains (in the Howjar region), featuring the best climatic conditions due to the different altitudes and rainfall zones, along with plenty of sunshine. Although frankincense trees grow in other regions of Oman, they are never as numerous or as high in quality as the trees in Dhofar.

Omani frankincense is often called “Al-Hojari” (sometimes “Hugari” or “Hujari”). The name could hail from Howjar, an area behind the mountain range that reaches towards the desert. This is where most of the top-quality greenish Al-Hojari frankincense comes from, owing to the minimal precipitation. The name could also be derived from the Arabic word “hajar” (stone).

Like Somalia, Oman could also be described as a land of frankincense. Omani people do not appreciate any comparison with Somalia, however, because there is a political frankincense war between the two countries and it’s officially prohibited to import frankincense from Somalia into Oman.

Although almost all types of frankincense come in different colors, most are not as striking as Omani frankincense: these range from greenish and whitish to honey, reddish and brownish. Sometimes, you can even find turquoise or pink tears.

The greenish, transparent, shimmering “Royal Al-Hojari” takes the top spot in quality. This variety is rare, accounting for only 3 to 5% of the total harvest. Even rarer is the turquoise Omani frankincense, which accounts for just 0.5% of the country’s harvest, depending on the year. We don’t often come across it, as it’s primarily sold within the country.

But the other abundant grades of Boswellia sacra shouldn’t be overlooked. The second grade is “Superior Hojari”, which is whitish, sometimes with a hint of yellow (although I personally wouldn’t deem this incredible frankincense anywhere near second rate). It is also called “Fusoos” — “pearl” or “silver frankincense”. The third grade is the amber-colored, reddish Oman frankincense, often called “Amber Hojari”. The fourth grade is the brownish, dark frankincense, which is called Black Frankincense or Shaabi, but also known as “Mughsayl” (a coastal town). It’s very intense and rich in essential oils — perfect for distillation.

There is no scientific explanation for the color range of Omani frankincense. Some sources say that the younger trees give off more greenish resin, but it is certain that the Qara mountain valley is where the most top grade, greenish frankincense is harvested. Frankincense trees in other regions also give off greenish resin, although in lesser abundance. This is undoubtedly due to the ratio of solar radiation to precipitation. While frankincense trees that get more water tend to give off brownish resin, the frankincense trees that grow in this special region with minimal rain and plenty of sunshine provide more greenish frankincense.