system
A chat on subreddit /r/me_irl
human
I work in cs for a company that has sold lab-grown diamond jewelry at times and we get returns for these like "oh, my local jeweler said these aren't real diamonds.."  Ah yes and I bet he then upsold you significantly on something they offered.
gpt
Apparently old handheld diamond testers register lab grown stuff differently. Even the new testers are hit and miss - old ignorant jewelers not keeping up with the times doesn't surprise me a bit. The profession has a lot of sexism and old thinking to root out. Plus.. Yea. Upselling.