It is interesting to compare the above weight percent image in the first post, in which the color scale was adjusted manually, seen here again:
![](https://probesoftware.com/smf/oldpics/i40.tinypic.com/mn2q7d.jpg)
With this image below, which are the same data but just displayed using the automatic log scaling with no adjustment. The only downside I can see to the log scaling is that you have to calculate the actual weight percents from the log values in one's head!
![](https://probesoftware.com/smf/oldpics/i39.tinypic.com/do9w7t.jpg)
For more information on point analyses of trace elements in quartz, see this post:
http://probesoftware.com/smf/index.php?topic=29.msg387#msg387