I found this hard clay like rock on my stroll along beach it has a sandalwood /fishfood /leathery kind of smell it is really cool the smell has worn off a little as dry now. I wonder if it is ambergris???/
I think you could be right.
Break a bit off and put it into water in an old container suitable for heating on a stove.
Put a thermometer into the water (one that goes to at least 100C - not a medical one).
Heat the water and watch the temperature and the lump.
If it is ambergris, it should melt at about 62 °C to a fatty, yellow resinous liquid.
That should be a good enough test. But if you like, you could keep heating the water.
If it is ambergris, at 100 °C (that is, as the water boils) it should evaporate as a white vapour (best not to breathe it).
You could also try setting fire to a lump of it; it should burn with a luminous flame.
(temperatures from http://en.wikipedia.org/wiki/Ambergris)
You can also, more easily, test it as in the following page
Let us know!
I have also discovered a similar rock along the beach and was hoping you could tell me if you managed to confirm whether your rock was indeed ambergris and how you did this.
If you feel uncomfortable replying to this post I am more than happy to give you my personal e-mail to message in private.
The presence of squid beaks is the best identifying factor though they are not always there. There are a lot of sea formed lumps of oils/fats that mimic ambergris but this site has the best information with the option fir testing and sale; http://www.ambergris.fr/identification_of_ambergris.html
You can also follow Mike's advice above.