What is Emerald?
{{Infobox mineral | name = Emerald | category = [[Beryl]] variety | boxwidth = | boxbgcolor = | image = Béryl var. émeraude sur gangue (Muzo Mine Boyaca - Colombie) -2.jpg | imagesize = 250 | caption = Emerald crystals from Muzo, Colombia | symmetry = (6/m 2/m 2/m) – Dihexagonal Dipyramidal | unit cell = a = 9.21 [[Ångstrom|Å]], c = 9.19 Å; Z = 2 | formula = Be<sub>3</sub>Al<sub>2</sub>(<nowiki>SiO</nowiki><sub>3</sub>)<sub>6</sub> | molweight = 537.50 | color = Green shades | habit = [[Crystal habit|Massive]] to well [[Crystalline]] | system = [[Hexagonal crystal system|Hexagonal]] (6/m 2/m 2/m) [[Space group]]: P6/mсc | twinning = | cleavage = Imperfect on the [0001] | fracture = [[Conchoidal]] | tenacity = | mohs = 7.5–8 | luster = [[Lustre (mineralogy)|Vitreous]] | polish = | opticalprop = Uniaxial (-) | refractive = n<sub>ω</sub> = 1.564–1.595,<br> n<sub>ε</sub> = 1.568–1.602 | birefringence = δ = 0.0040–0.0070 | dispersion = | pleochroism = | fluorescence= None (some fracture filling materials used to improve emerald's clarity do fluoresce, but the stone itself does not) | absorption = | streak = White | gravity = Average 2.76 | density = | melt = | fusibility = | diagnostic = | solubility = | diaphaneity = Transparent to opaque | other = | references = <ref name=Mindat>{{cite web|url=http://www.mindat.org/min-1375.html |title=Emerald at Mindat |publisher=Mindat.org |date=2010-07-19 |accessdate=2010-07-30}}</ref> }} An '''emerald''' is a [[mineral]] [[gemstone]] and a variety of [[beryl]]. It is the birthstone of someone whose birthday is in the month of [[May]]. It is a [[green]] crystal. The emerald is one of the most valuable [[gem]]s, along with the [[ruby]], the [[opal]], [[topaz]], the [[diamond]], and a [[sapphire]]. == Etymology == The word ''emerald'' comes from [[Vulgar Latin]]. The word was Esmaralda/Esmaraldus, a different way of saying the Latin word ''Smaragdus'