Where Methyl Ionone Gamma Coeur is the most floral and sweet of the methyl ionone family, Methyl Ionone Alpha Extra is the bolder, more leathery and orris member of the family. Use this slightly more expensive product when you seek a strong note of iris with more complexity and richness. The power behind this product is that it contains the highest quantity of the Alpha Methyl Ionone isomer (CAS 7779-30-8) while Methyl Ionone Gamma Coeur contains the highest amount of the weaker Alpha Isomethyl Ionone (CAS 127-51-5). Iralia®: Finest and sweetest all round iris / violet chemical. Historic.Methyl Ionone Gamma Coeur: Cheapest. Floral, violet, soft, powdery.Methyl Ionone Alpha Extra: Bolder, orris, leather, beeswax. Diffusive. Long lasting.