Exo-THC is available as a certified standard since some times now.
Before, if I’m not confusing, it used to be presented as a a sort of THC metabolites, convenient to use in forensic drug tests. Now they present it as an impurity formed in d9-THC synthesis… That is actually a minor impurity (generally < 2%), from what i’ve seen so far.
In general CBD products (flowers, extracts, tinctures etc), it is absent, or only present as trace (<0.01%).
Look like it is 99%+. 
That looks like the D-10 I have. Nice white and fluffy. Sparkling when viewed up close. What do you use to wash it? I used heptane at -86°C. Also does your D-10 turn yellowish after about 6 months or so? I’ve even had some D-10 turn a very light tint of pink/ peach type of color. What would that be if you don’t mind me asking.
Looks like plaster from the ceiling
Plasterdabs4science
This could be delta-10, depends on the method conditions and flow rate - on our method d10 peaks elute just before cannabichromene at 7.33 min. This is via the Shimadzu Cannabis Analyzer HPLC gradient high resolution method, where delta-9 elutes at 6.60 min and THCA elutes at 7.45 min.
source - I ran samples for over a year at a lab in NV and saw a lot of this peak in low quality distillate. Now working for a producer/extractor and we are trying to minimize and inhibit d10 formation when producing distillate with a BR system. Other than decreasing heat we haven’t yet identified any other factors to control it…
