Who we are
280 years of trading tradition.
Carat Investments is part of Retter Inc., Switzerland. Our foundation is the traditional trading network of the Schupp Family Office from Pforzheim — with a history dating back to 1744.
1493
The earliest traces
The Schupp family coat of arms first appears in the Armorial Général in Liège, Belgium — featuring a silver shield, two red roses and a steel-blue helmet. The oldest known roots of the dynasty.
1744
The founding
Carl Schupp is born in Fischbach an der Nahe, son of a goldsmith. Church warden and smith — he establishes the family's goldsmithing tradition, even before Pforzheim becomes a jewellery city.
1898
Rudolf Schupp founds the firm
On April 1, 1898, Rudolf Schupp establishes his own gemstone cutting workshop and trading house in Idar-Oberstein. At its peak, up to 50 lapidaries work in the workshop.
1899
The legendary aquamarine
In Brazil, Rudolf Schupp discovers a large blue rough stone on the outer wall of a hut — a valuable aquamarine. With the proceeds of 900 gold marks, he commissions a four-storey Art Nouveau house with an attached factory building.
1902
The Brazil empire
Brother Emil "Emilio" Schupp emigrates to Brazil and becomes a pioneer of the Brazilian gemstone industry. He discovers several aquamarine mines in Minas Gerais — including the world-famous Santa Maria mine.
1921
The million-dollar heist
Four armed robbers raid the jewellery store on Maiden Lane in New York. Jewellery worth over one million dollars is stolen. The loot remains missing — until 35 years later, a stolen necklace resurfaces at the Paris boutique on Place Vendôme.
1945
Pforzheim in flames
The branch at Bahnhofsplatz is completely destroyed by incendiary bombs. In the fifth-floor safe: gemstones scorched, jewellery in platinum, gold and silver fused into a single nugget. The firm rebuilds.
1968
Royal commissions
Emissaries of the Queen of England inspect the firm, photograph credentials with Minox spy cameras, and commission repairs on Crown Jewels. Some orders are fulfilled overnight.
2008
The next generation
Frank-Jürgen Schupp takes over as sole proprietor — the youngest publicly appointed gemstone expert in the 4th generation. With over 1,200 gemstone varieties and a network built across generations.
2024
Carat Investments
The storied trading heritage is reimagined: Carat Investments emerges as an institutionally structured access point to the secondary market for colored gemstones — as part of Retter Inc., Switzerland. 280 years of market depth meet modern investment structures.
Our values
Discretion
Every transaction and every relationship is handled with absolute confidentiality.
Excellence
Only stones that meet our rigorous quality and certification standards.
Integrity
Transparent pricing and honest advice — without conflicts of interest.
Get to know us.
Schedule a consultation