The correspondence between elite level names and precious metals is far from standardized. Gold, for example, designates AA's lowest elite level, Delta's middle level, and the top level at both bmi and BA - but BA's is harder to earn than bmi's. Assuming AA and DL were both willing in principle to comp the other's elites, AA would surely give its Gold to a Delta Gold Medallion, but no way would DL give Gold Medallion status to someone holding "only" AA Gold AAdvantage status. Some airlines use designations that don't involve precious metals at all: "Chairman's Preferred," "Premier 1K," "Senator," etc. Perhaps you could rephrase your question in a more meaningful way?