[1] The piece caught the attention of Frederick Henry, Prince of Orange, at the time Stadtholder of The Hague, who agreed to buy it for the large sum of 27,000 guilders.

As a result of his prowess, Cletcher became Dean of the Guild of Gold- and Silversmiths in 1630 at the age of only 32,[3] a position which he skillfully leveraged to make connections with various European noble houses.

Cletcher kept extensive notes on his trades and produced drawings of the most notable objects,[4] the majority of which survived and are held today by the Museum Boijmans Van Beuningen in Rotterdam.

Henrietta Maria traded one of England's most impressive pieces of jewellery–the hat jewel known as the Mirror of Great Britain–to Cletcher, who recorded the item in his sketchbook with the note that it had been "commissioned by Coninc Jacobus" (Charles' predecessor James VI and I).

[7] In 1644, he engineered the purchase of the 35-carat Beau Sancy diamond–the smaller sibling to the Sancy–from the estate of the late Marie de' Medici by Frederick Henry, whose appetite for luxury had grown with the successes of the Dutch Republic.

Cletcher recorded the transaction with great satisfaction in his notebook, as he believed the jewel to in fact be worth 150,000 guilders, making the sale a true bargain for his benefactor Frederick Henry.

[8] In addition to his activities as a jeweller, Cletcher was also a skillful investor in schemes such as the draining of marshland in the Poitou region of France, milling in Sweden, and various real estate purchases.