I copied this charm from a book of Highland (Gaelic) verse in translation. This particular translation is by Alexander Carmichael and was reported as being from his "Carmina Gadelica", but I have yet to find it there.

KEPPOCH CHARM STONE INVOCATION

Let me dip thee in the water,
Thou yellow, beautiful gem of power!
In water of purest wave,
Which pure was kept by Bridget.

In the name of the Apostles twelve,
In the name of Mary, Virgin of virtues,
And in the name of the High Trinity,
And all the shining angels,
A blessing on the gem,
A blessing on the water, and
A healing of bodily ailments to each suffering creature.

This charm is of interest to me because the same practice of charming away illness with a stone is reported in the kirk session records in the parish where my family was living at the time. I quote the records here, spelling unchanged, emphasis added.

“John Young, in the Valleyfield, delated for charming, summoned, called, and appearing, interrogated as to his charming, declared as follows—viz., that being some time ago called to cure a certain sick person, he used these words: ‘ Little thing hath wronged thee, nothing can mend thee but Father, Son, and Holie Ghost, all three, and our sweet Lady. In etemitie let never wax, but away to the waine, as the dew goes of yeard and stane. I seek help to this distressed person in thy name.’ He likewise acknowledged that he used the same words in curing of a woman in the Blaire, who was for years thereafter weell; and that by the same words he cured Robert Bruce in the Shyres miln,—and the disease these persons had, he said, was a splen, which he siemed to the session to understand as of a disease put upon them through envy and splen. And being interrogat if he used any gestures or postures whiles he was pronouncing these words, he could not deny but that first he rubbed his own hand upon a bare stone, and rubbed the breast, stroaking it 3 times, of the person affected, and siemed to say that he prescribed the use of some herbs to the patient. The session did unanimously conclude him guilty of charming; whereupon being again called, the minister did endeavor to hold out the evill of his way, telling him that his cures were not effected without the help of the devill, and not only to forbear the same in tyme comming, but to mourn before God, and to seek mercie through Christ for using of the divel's prescriptions, and that the witches and warlocks used God's words and made mention of the name of God and Christ in theire services; and he being removed, the session did think fit to advise with the presbetrie how to carrie with him.”
28 August 1693.

(from David Beveridge, "Culross and Tulliallan", vol.ii, p.19)

Some other examples of curing stones and associations (?) with Celtic saints.