Hi Laura,

Here are some answers for Palaeontology at the Natural History Museum, London. I will ask my colleagues how they organise the minerals collection. Rock and Ores, for which I am in charge, are organised in a self indexing system that stores them in order of acquisition with a date related registration number.

1)	How are Earth Science Collections curated and organized?  I said
mainly defined by taxonomy, geographical origin, Storage and Stratigraphic age (based on the Synthesys classifications) Are there any more?

Our collections are broadly organised by higher taxonomic classification (Brachiopoda, Cephalopoda, Plants etc - do you want me to send entire list?) with some other more general collections eg Micropalaeontology and Palaeoecology (the latter for assemblage often slab materials that cannot be broken up into the constituent higher group because several are present).
Within each area of the collection there are a variety of different system for organisation based mainly stratigraphically and then by taxonomy but there are some collections that are ordered by taxonomy or locality. Most collections have been "broken up" so their constituent parts are distributed according to the higher classification so there are very few collections organised by the collector's name. Some large collections or collections that fit nicely in a higher category have been kept together so I would add to your list: Named collection. (eg The BP Microfossil Collection or The Giles Miller Collection (there isn't one of those btw!))

2)	What is the minimum information that would be required in World
collections catalogue for the discoverability of Earth Science collections and for a research to locate particular collections of interest.
We recently defined a set of 1-5 digital  information categories which are: None, Placeholder (a number only), Inventory (so they can be discovered in the collection), Core (Digitally Discoverable), Enhanced.
For digitally discoverable we have the following (nb I'm not sure I agree with all of these, particularly see comments below re: stratigraphy):

Species
Genus
Author
Type Status
Province / State / Territory
County
Specimen Count
Kind of Object
(Archaeological period)
LithoStrat Supergroup
Formation
Group

3)	What descriptive information should be considered mandatory or
desirable for each Collection?
I attended the TDWG collections BBQ work meeting on the Collection Descriptions and they had some questions about the necessary granularity of information for Identifying Earth Science Collections. For example they have included terminology for stratigraphic beds but I personally think this is too granular for Collection level information - considering the effort needed to fill in such data in a catalogue.  I will send feedback from the TDWG bbq as a separate email.

This is interesting to see that TDWG have been discussing stratigraphy. You can see above that we have included lithostratigraphic terms but I agree that these are too prescriptive. I would argue that a relevant chronostratigraphical level is enough. As it is, you cannot make some of the terms eg SuperGroup as required as these are not always defined and a similar situation with Group. As has already been mentioned, we are a long way from a dictionary of agreed local lithostrat terms.

All the best,

Giles