Emeralds

Recently I met Bill McGrath, a grad student at UVA, who specializes in the history of Tibetan Medicine. In recalling our conversation about the identification of the gem, vaidurya, I pointed out that in the modern Tibetan Medical tradition, this gem is identified as star sapphire rather than blue beryl, which is how Western Academic scholars have habitually identified this gem in absence of Tibetan sources upon which to rely. Spurred by our conversation, I chanced to look at the Wiki entry for beryl. The green variety of beryl is emerald. In Tibetan, emerald is called margad (མརྒད). This is clearly a non-Tibetan word, so from what language does it derive? The Wiki entry offers a few options, citing the Precious Stones for Curative Wear by W.T. Fernie M.D. Here, Fernie shares with us an entry by Dr. W. Rowland on page 127:

"' Smaragdus'....a clear transparent Gem; very beautiful, and the most brittle of all Gems. It stops (being drunk) all Fluxes whatsoever, chiefly the Dysentery, whether they come from a sharp humor, or venome ; and it cures venomous Bitings. For a Dose—six, eight, or ten grains are given. Among Amulets it is chiefly commended against the Epilepsie; it stops bleeding if held in the mouth ; it cures all bleedings, and dysenteries ; it expels fears, and the Tertian Ague, if hung about the neck. There is a' Prepared Smaragd; and a Tincture of Smaragd.' "

If we turn our attention to the Online Etymology Dictionary, we find the following statement:

emerald (n.) 

"bright green precious stone," c. 1300, emeraude, from Old French esmeraude (12c.), from Medieval Latin esmaraldus, from Latin smaragdus, from Greek smaragdos "green gem" (emerald or malachite), from Semitic baraq "shine" (compare Hebrew bareqeth "emerald," Arabic barq"lightning").

Sanskrit maragdam "emerald" is from the same source, as is Persian zumurrud, whence Turkish zümrüd, source of Russian izumrud "emerald." For the excrescent e-, see e-.

In early examples the word, like most other names of precious stones, is of vague meaning; the mediæval references to the stone are often based upon the descriptions given by classical writers of the smaragdus, the identity of which with our emerald is doubtful. [OED]

Emerald Isle for "Ireland" is from 1795.

http://www.etymonline.com/index.php?term=emerald

We can be certain that the Tibetan source of the term is Sanskrit. And it seems ultimately the Sanskrit term derives from the Greek. Interestingly, the Tibetans also identify a "stone" margad as malachite. 

And this in turn raises the question— from what language is the name mu men (མུ་མེན)? This is the Tibetan name for lapis lazuli, a gem frequently misidentified as vaidurya by translators.