ANSWER: Interestingly, for all its use in certain religious circles, the balm of Gilead is reference in only three places in the King James Version Old Testament. The balm is only mentioned in Genesis 37:25, Jeremiah 8:22 and 46:11.
And they (the sons of Israel) sat down to eat bread. And they lifted up their eyes and looked. And behold, a company of Ishmaelites (primarily those descended from Ishmael, the son Abraham had through Hagar) came from Gilead with their camels bearing spices and balm and myrrh, to take them down to Egypt (Genesis 37:25, HBFV)
21. For the shattering of the daughter of my people have I been shattered (in heart). I mourn, dismay has taken hold of me. 22. Is there no balm in Gilead? Is there no physician there? Why then has the healing of the daughter of My people not come? (Jeremiah 8:21 - 22)
10. For this is the day of the Lord GOD of hosts, a day of vengeance, that He may avenge Himself of His foes . . . Go up into Gilead, and take balm, O virgin, the daughter of Egypt: in vain shalt thou use many medicines; for thou shalt not be cured (Jeremiah 46:10 - 11)
The Hebrew word for balm is tsoriy (Strong's Concordance #H6875) and comes from an unused root word meaning to leak or crack. A generic definition is that it is an aromatic salve or ointment derived from a plant (or a tree) that may (though not always) be used for its believed medicinal properties. An example of a non-medicinal use of a fragrant balm ointment is when some was made in order to embalm Jesus' dead body and mask the smell of decaying flesh (Luke 23:56).
The Gilead balm you are asking about is believed by some to have been first brought from this region of Israel by Ishmaelite traders traveling in a caravan to Egypt (Genesis 37:25). It was to these merchants that Israel's sons sold their brother Joseph in the hope that they would no longer have to deal with him (see Genesis 37).
The region of Gilead was noted for this ointment, a secretion of the balsam tree. The territory where this salve came from (an area north of the Salt (Dead) Sea in the land of Israel) was originally given by God to Manasseh as an inheritance when the children of Israel entered the Promised Land. It was used in various healing mixtures and sold to various countries like Egypt.
It is possible that this ancient trade item of Gilead balm is now known as the Balsam of Mecca. This resinous balsam product originated from trees that grew in Palestine and in the southern part of the Arabian Peninsula. The most known location that produced this type of ointment was the city of Ein Gedi (located on the western shore of the Dead Sea).
This product was used both for medicinal purposes and for a perfume by ancient Greek and Roman cultures. Pliny the Elder (23 to 79 A.D.), a Roman army commander and author, mentions the balsam as an ingredient in the Parthian Empire's "Royal Perfume." There is no profound truth in the Scriptural references to the balm of Gilead. People generally have their own references when it comes to healing and this ointment is one of them.