What are these rocks?

Question

i would just like to ask some help for my assign.

What are the physical and chemical properties and what type of rock are these:

Agate, Amber, Citrine, Opal, Turquiose.

Thanks!

Answer 1

For Agate:

http://www.agatelady.com/agate-basics.ht...

Amber is not a rock; it is hardened tree sap.

For Citrine

http://www.jewelrysupplier.com/2_citrine...

For Opal:

http://www.galleries.com/minerals/minera...

For Turquoise:

http://www.jewelrysupplier.com/2_turquoi...

This is a good site to read:

http://www.amonline.net.au/geoscience/ea...

Answer 2

None of these are rocks, they're minerals except amber which is tree sap. Agate, citrine and opal are all silicates which means they are made of silicon dioxide (SiO2). Agate often shows bands of colours when cut and polished. Citrine is a yellow variety of quartz and is extremely rare. Opals come in a variety of colours but are most often blue or red-orange. These three minerals are all vitreous (glassy) in lustre.