I was asked by an East Kingdom Gazette reader whether “gemstone” names were used in period. Broad questions like this are always somewhat hard to answer, because different cultures adopted different naming styles at different time periods. What I can say is that, in some times and places, parents named their children after gemstones.
Some examples of gemstone names are below. Note that these are simply examples. Not finding a particular time period or culture among these examples does not mean that additional research by a specialist in that language will not turn up evidence of a particular gemstone name.
The names Ruby and Sapphire are found as female names in late period England. Pearle appears in late-period England as a male name.
The Italian word for “emerald” is found in records as a male name, Smeraldo, and as a female name, Smeralda.
Interestingly, “diamond” seems to be the most popular gemstone for period names. There are 13th and 14th century English examples of Diamanda as a female given name. Diamond appears as a male given name in 16th century England. Diamante is found as a female given name in 16th century Germany and 13th century Italy.
 Ruby [no surname]; Female; Marriage; 16 May 1581; Saint Andrew, Plymouth, Devon, England; Batch: M00183-1 (https://familysearch.org/ark:/61903/1:1:N2ST-Y8J).
 Sapphire Hill; Female; Marriage; 26 Jun 1638; Morval, Cornwall, England; Batch: M05293-1 (https://familysearch.org/ark:/61903/1:1:N2LL-XXY); Sapphira Norkin; Female; Burial; 12 Oct 1635; St. Dunstan, Stepney, Middlesex, England; Batch: B02857-4 (https://familysearch.org/ark:/61903/1:1:JCV2-13P).
 Pearle Neale; Male; Marriage; 25 Jul 1621; Saint Andrew By The Wardrobe, London, London, England; Batch: M02232-1 (https://familysearch.org/ark:/61903/1:1:NK7B-JZB).
 Names in 15th Century Florence and her Dominions: the Condado by Julia Smith (SCA: Juliana de Luna) (http://www.s-gabriel.org/names/juliana/condado/mensalpha.html).
 Late Period Italian Women's Names: Florence by Julia smith (SCA: Juliana de Luna) (http://medievalscotland.org/jes/Nuns/Florence.shtml).
 Diamanda is found in Feminine Given Names in A Dictionary of English Surnames by Brian Scott (SCA: Talan Gwynek) (http://heraldry.sca.org/names/reaneyAG.html) dated to 1221 and 1349.
 Diamond Diamonde; Male; Christening; 08 Aug 1563; Stoke by Nayland, Suffolk, England; Batch: C06314-2 (https://familysearch.org/ark:/61903/1:1:NB4D-QR6).
 Diamante Garniche; Female; Christening; 05 Apr 1573; Evangelisch, Frankenthal, Pfalz, Bavaria; Batch: K98429-2 (https://familysearch.org/ark:/61903/1:1:NK7M-1P2).
 Feminine Given Names from Thirteenth Century Perugia by Josh Mittleman (Arval Benicoeur) (http://www.s-gabriel.org/names/arval/perugia/perugiaFemAlpha.html).