Tantallon. I have not read much about the granite factor but I did see this on the LN compositions. As an average their were the grades reported by Micon for LN and L1. Imagine the differing zones and strikes as they dig. The block models etc.

From the Jan 06/10 NR

"A preliminary metallurgical evaluation was conducted by SGS Mineral Services ("SGS") for the Langmuir North deposit and the results are summarized in a report entitled "An Investigation into the Recovery of Nickel and Copper from the Langmuir #2 North Zone" dated June 25, 2009 (the "SGS Report"). A copy of the SGS Report can be viewed under the Corporation's profile on the SEDAR website (www.sedar.com).

According to the SGS Report, most of the nickel value is contained within the mineral millerite, a mineral with a high nickel content which is somewhat different from other deposits known to date for the region. Excellent recoveries of nickel sulphides are obtained at a relatively coarse grind.

Based on the SGS Report and on previous historical work and metallurgical recoveries from previous production from the area, the Corporation believes that a platinum-palladium and a cobalt credit from the concentrates is possible.

SGS on their Langmuir North met study...pages 18/19