The red grape variety is an interspecific new variety between Diana (1) x Chambourcin. Synonyms or breeding numbers are Geilweilerhof 67-198-3 and GF 67-198-3. It contains genes of Vitis labrusca, Vitis lincecumii, Vitis rupestris and Vitis vinifera. The hybrid was crossed in 1967 by Dr. Gerhardt Alleweldt (1927-2005) at the Institute Geilweilerhof in Siebeldingen/Pfalz (Germany). The name derives from the famous diamond (140.5 carats) that was on the crown of Louis XV (1710-1774) at his coronation in 1722 and which Marie-Antoinette (1755-1793) later wore frequently. It also adorned the rapier pommel of Emperor Napoleon Bonaparte (1769-1821), and today the diamond is in the Louvre in Paris. The variety was a crossing partner of the three new varieties Calandro, Julius and Reberger.
Serious sources on the internet are rare - and Wine lexicon from wein.plus is one such source. When researching for my articles, I regularly consult the wein.plus encyclopaedia. There I get reliable and detailed information.Thomas Götz
Weinberater, Weinblogger und Journalist; Schwendi