Thousands of pure gold is a very high purity gold symbol, and those with a gold content of not less than 999 are called thousands of pure gold. It is the highest value in the naming of jewelry color, and the letter L behind it is the code name of the foundry.
Distribution of gold
Natural state gold usually appears in the form of its element in nature, that is, the metallic state, but it often forms an alloy with silver. Natural gold usually contains 8 to 10% silver, and the silver content exceeding 20% is called silver gold. When the silver content increases, the color of the object will become whiter and lighter.
Source When the ore contains natural gold, the gold will be hidden in the rock in the form of granular or micro-particles, usually occurring at the same time as sulfide veins such as timely or pyrite. The above situation is called vein deposit or vein gold. Natural gold will also appear in the form of leaves, particles or large gold nuggets, which will be eroded from rocks and finally form gravel of alluvial deposits, called placer gold or alluvial gold.
Placer gold will definitely contain more gold than the surface of vein deposits, because the adjacent minerals of gold in rocks are oxidized, weathered and washed and flow into rivers and streams, where they are collected and combined by water to form gold nuggets.
Gold mine gold sometimes exists in nature in the form of compounds, especially gold telluride. Examples are needle tellurite calaverite, needle tellurite sylvanite, leaf tellurite nagyagite, tellurite petzite and white tellurite krennerite. Gold rarely appears in amalgam with mercury, and it also appears in seawater at a low concentration.