Otago Community Hospice gala charity organiser Emeritus Prof Martin Ferguson said most of the gold was donated by dental surgeons and dental laboratories, along with unwanted jewellery from the public.
The dental gold, which also contains other metals such as platinum, was sent to a refinery where it was analysed, the percentage of gold calculated and then exchanged for 18-carat jewellers gold.
The remainder of the gold in Mr Bosshard's weighty pieces was purchased with donated funds.
The jeweller said he had planned to make something "really exciting'' for the auction but eventually settled on the necklace and bangle, made in two of his best classical designs.
It had taken him half a lifetime to perfect the designs and the other half to realise he could not improve them further, he said.
"I regard them as the best things I can do. If I'm ever going to be known beyond my lifetime, it will be for these sort of things.''
While he had crafted many bangle and necklace designs in silver, he had not made many in gold, Mr Bosshard said.
The jewellery will be auctioned with other donated art, cars, sports memorabilia and some interesting items such as botox injections and wisdom-tooth extractions.
Prof Ferguson said the auction was not just about raising money but also the profile of the hospice.
Many people had little idea of what the hospice did, thinking it was just a place people went for their final days. Some also went there for respite care or to get medication levels adjusted.
Aside from the 12 in-patient beds, hospice staff were presently visiting about 130 patients in their own homes, he said.
The gala auction will take place on May 17 at the Scenic Circle Southern Cross Hotel in Dunedin.
More details can be found at www.otagohospiceauction.org.nz.
