Quenya 

sar

(small) stone

sar (sard-, as in pl. sardi) noun "(small) stone" (SAR). In Elessar, q.v. Since Tolkien let this name have a stem in -sarn- (genitive Ele[s]sarno, VT49:28), he may seem to have changed the stem-form of sar from sard- to sarn-.

Elessar

elf-stone

Elessar masc. name "Elf-stone" (Elen + sar, actually "Star-stone", cf. Elendil concerning elen "star" being used to mean "Elf") (LotR3:V ch. 8). Genitive Elesarno _(VT49:28, read _Elessarno?) indicates that the stem is -sarn-. As a common noun, elessar or "elf-stone" may signify "beryl" (in the chapter Flight to the Ford in the LotR, Aragorn finds "a single pale-green jewel" and declares: "It is a beryl, an elf-stone"). Elessar as a name may also be seen as a pun or variant of Elesser "Elf-friend".

Sindarin 

edhelharn

elf-stone

(a term for beryl) edhelharn (pl. edhelhern) (SD:128-31).

edhelharn

elf-stone

(a term for beryl) edhelharn (pl. edhelhern) (SD:128-31). SEEING STONE (palantír) *gwachaedir (i **wachaedir), no distinct pl. form except with prefixed article (in gwachaedir), coll. pl. ?gwachaediriath or ?gwachadirnath (the latter form assuming that -dir is reduced from older -dirn) The form occurring in the primary source, gwahaedir, must represent the late Gondorian pronunciation with h for ch** (PM:186).