The Folch Mineral Collection was known during the period 1960–1980 as one of the best private mineral collections in the world. It was famous for its size, over 15,000 specimens, the quality of the pieces, the large number of classic specimens that are now almost impossible to obtain, and the surprisingly modern style of the collection.
Mr. Joaquín Folch i Girona collected during a period when the style of most mineral collectors in Europe consisted of gathering large specimens of rare minerals, with aesthetics and perfection considered less important. He tended instead to collect smaller specimens that were aesthetic and, where possible, damage-free. This approach gave the collection a distinctive character in quality, colour and crystal integrity.
On the death of Mr. Folch in 1984 the collection passed to his son Alberto, and when Alberto died it passed to his grandson Joaquín Folch, who wisely decided to keep the collection exactly as his grandfather had it, including the display cases. The collection was therefore kept together and its great historical value was not lost.
In 2005 the Folch family had the idea of updating the collection to include more modern material. Since 1984 nothing new had been added, creating a significant gap in minerals discovered since then. The update was intended to add new species, localities and aesthetic specimens while preserving the integrity of the historic collection.
The Folch Collection is dominated by classic European mineral specimens, with emphasis on crystal form, colour, lustre, transparency and freedom from damage. It contains many specimens from classic 19th- and early 20th-century localities such as Cornwall in England, Saxony in Germany, Elba in Italy, the Swiss Alps and Minas Gerais in Brazil.
Representative pieces include a chrysoberyl twin from Santa Teresa, Espírito Santo, Brazil, with excellent colour, lustre and transparency, about 3.2 × 2 × 1.8 cm, and prismatic pyromorphite crystals from Bad Ems, Germany, about 1920, with the colour typical of the locality, excellent lustre and very clear crystals, accompanied by an old label from S. Henson of London. These specimens show that the collection valued locality, historical labels and aesthetic quality as well as species diversity.
The Folch style influenced later private collections and museum displays. It demonstrated that small, complete and aesthetic specimens can have scientific and collector value comparable to large rare pieces, and it helped shift mineral collecting from a focus on large rarities toward aesthetic quality.
The integrity of the collection reflects three generations of continuous care. Alberto and Joaquín Folch did not disperse or sell the core collection but retained the original display cases and labels, preserving historical information. For mineral collections, original labels, locality records and display arrangements are themselves important scientific records that help trace specimen provenance and circulation.
The post-2005 update was led by the family with the aim of adding minerals discovered since 1984 and new aesthetic specimens. The update did not replace the historic collection but added contemporary content within the existing framework, giving the collection both historical depth and modern completeness.
The Folch Collection has been exhibited at European mineral shows and museums, notably Expominer in Barcelona. Specimens have been used for mineralogy teaching, locality research and collection-history studies, and some are illustrated in publications such as Mineral Museums of Europe.
Its research value lies in three areas: it provides reference specimens from many classic localities for comparison with modern analyses and historical records, it preserves 19th- and 20th-century labels and transaction records that document the mineral market, and it shows the role of private collections in the circulation of mineralogical knowledge, demonstrating that collections outside museums can also preserve and advance scientific material.