Dinosaur technology remains
Dewix > "Diamonds aren't very big, tend to be brittle & can be erroded and what connects them would dissolve or corroded in a blink of a geological eye."
However, zirconia are very robust, many having survived repeated tectonic activity. So, althogh also tiny, a cut and fashioned zircon gemstone could theoretically survive the many millions of years necesary to provide evidence of dinosaur techniloigcal advancement. Assuking they wore jewellery.
> "a few grains of zircon found in the early 1990s in a sandstone from western Australia dates back 4.2–4.3 billion years"