Answer:
Explanation:
Geologists defines a mineral as a naturally occuring solid, which is inorganic with a uniquely ordered structure and a definite chemical composition. 
Gold nugget based on this definition is mineral. It is a solid and it occurs naturally. It is made up of gold atoms. 
Seawater is not a mineral. It is a liquid and does not have definite composition. 
Quartz is a mineral with a definite composition. It occurs naturally and it is a solid. 
Cubic zirconia is not a mineral. It is not naturally occuring. It is man made. 
Obsidian is not a mineral. It is a mineraloid due to its form. It is glass-like in nature. In obsidian, the crystals do not have time to form an ordered structure. 
Ruby is a silicate mineral. It is naturally occuring and fits the description of minerals. 
Glacial ice is a mineral. It is solid, inorganic, naturally occuring, and has a definite composition. 
Amber is an organic compound and not a mineral.