The S&P/ASX All Ordinaries Gold Index (XGD) includes companies...

The S&P/ASX All Ordinaries Gold Index (XGD) includes companies from the gold sub-industry of the All Ordinaries Index and simply serves as a broad market indicator for the gold industry.

The index follows the broader All Ordinaries index methodology, therefore companies included in this index are not filtered for liquidity or adjusted for freefloat. The median market cap of the XGD index is c.$300m, and the mean market cap of the index is c. $1.6b.

Effectively it provides a benchmark for the Australian gold sector.

https://us.spindices.com/indices/equity/all-ordinaries-gold-sub-industry