Find the odd one out . Give a reason for your answer.

1. cuprite, quartz, haematite, and bauxite
2. gabbro, basalt, conglomerate and granit
3. Shale, marble, dolomite and sandstone
4. Slate, granite, marble and guartz
5. ruby, graphite, sapphire and emeraled

1) odd man is quartz

cuprite, haematite, and bauxite are ores of element Cu, Fe and Al

2) odd man is conglomerate (sedimentary rock) 

1. gabbro, basalt,  and granite are example of igneous rock.

3) odd man is  marble (metamorphic rock)

1. Shale,  dolomite and sandstone are the example of sedimentary rocks

4) odd man is guartz (mineral)

1. Slate, granite, marble are the example of rocks

5) odd man is graphite (allotrope of carbon)

1. ruby, sapphire and emeraled are example of precious stone