History · Geology
About Mengyin Diamond Mine
The Mengyin Diamond Mine in Mengyin County, Shandong Province, was China’s first commercial diamond producer and is one of only two confirmed kimberlite-hosted diamond fields in the country (the other being Wafangdian in Liaoning). Discovered in 1965 and operated through the 1990s/2000s, the Mengyin pipes produced the bulk of Chinese gem and industrial diamond between 1970–2000, including the famous “Changlin Diamond” (158.7 carat, 1977) — China’s largest historical diamond. Mengyin establishes Shandong as the encyclopedia’s 13th Chinese province with a published locality entry.
Geology & Signature Specimens
The deposit consists of approximately 30 small kimberlite pipes intruded into Cambrian carbonate sequences during the Late Ordovician to early Silurian. Diamonds occur as octahedral and dodecahedral crystals, mostly under 5 mm but with occasional gem-quality stones. Indicator minerals include pyrope garnet, olivine, phlogopite, and ilmenite — all diagnostic of mantle-sourced kimberlite. Most production has now been depleted; minor exploration continues for deeper pipes.
Minerals Produced Here
- Diamond (金刚石)
- Forsterite (镁橄榄石)
