Also worth checking out, the $10 Open Source spectrometer that attaches to your phone.<p><a href="http:&#x2F;&#x2F;store.publiclab.org&#x2F;products&#x2F;foldable-mini-spectrometer" rel="nofollow">http:&#x2F;&#x2F;store.publiclab.org&#x2F;products&#x2F;foldable-mini-spectromet...</a><p>The challenge seems to be to understand how to interpret the results. SpectralWorkbench.org is place that folks are sharing scans and comparing.<p><a href="http:&#x2F;&#x2F;spectralworkbench.org&#x2F;" rel="nofollow">http:&#x2F;&#x2F;spectralworkbench.org&#x2F;</a>