[MarianaM (OP)]

Willow is asking...

I have found a grey pebble with lots of shiny flecks that look like silver. How do I find out what it is?

Can you help?

[Hayseed]

It will depend on Willow's age, present knowledge and the purpose/context for the wanted knowledge.

The easiest thing to do, depending on context, is to supply clear scaled photographs to the right pair of eyes.

Or post on forums and hope the right pair of eyes sees the post.

If Willow is a true mineral hound, then observation and measuring equipment, plus analytical chemistry skills.   Mineral forums. 

[Iwonda]

Would recommend getting an electron scan analysis. S.E.M. is cheaper but will require your specimen to be coated with carbon. EDX analysis will give the same result without coating but may cost a bit more. Both are nondestructive testing and will tell you exactly what the shinny material is. Hope this helps.