The difference between quartize and marble?

Question

I have a prob. at school.

a quartzite and a marble are both white and looks exactly the same. I know quartzite is just quart metamorphed and marble is the same where as marble consists of calcite.

However, i put acid on the marble and the calcite did not react and fizz. Bu even stranger is the marble and the quarts both scratch glass.

I cannot tell the diff. between two white/crystal looking minerals of quartzite and marble plz help.

Thanks

Answer 1

White marble and white quartzite may look similar superficially, but they

are actually very different and easy to tell apart.

1. Quartzite is harder and will scratch glass. Marble will not.

2. marble will fizz gently in dilute (10%) hydrochloric acid. You may need

to scratch the surface, and look at it with a hand lens. Be careful. Even

dilute acid can hurt your eyes and rot your clothing.

These are just two of the obvious differences. Marble is made of calcite or

dolomite (or both) and quartzite is made of quartz. The crystals of these

three minerals have different shapes, and the quartz crystals are shinier.

You can find out more about telling the differences among minerals with an

introductory college level mineralogy textbook. Some books for mineral

collectors are also helpful.

Hope this helps.

Answer 2

If it doesn't fizz it isn't marble

quartzite will have distinguishable grains (sandstone texture)

marble has no distinguishable grains to naked eye

Check your acid: should be 10% HCl.

Answer 3

Marble is carbonate, quartzite is silicate.

If your marble scratches glass, there is some

included silicate sand.

Use a stronger acid, (careful), on your 'marble'.

You might find you've got a sandstone.

Answer 4

pl. use dil. hydrofluoric acid over a clean surface.

In case the marble is dolomitic you would not get effervecence.

Also scratch one rock with other, you would find that marble would not scratch quartzite.

thnks