My understanding is that the book value of the company's assets...

My understanding is that the book value of the company's assets are not based on its market cap rather are calculated using the prevailing gold price and mining costs at the time to project forward what the deposit is worth.

So if the calcs are up to date (which they roughly are) a lower price to book value is a very good thing (assuming gold and operating costs stay at current levels).

So I don't expect to see further write downs, especially given they had $260m write down not long ago.