I put both Lucky Strike and Valley View thundereggs on the same page because they are similar due to the close proximity of the mines. The Valley View thundereggs appear to have biconoid agate cores while those of Lucky Strike contains more pointed agate cores. Valley View mine is already closed while Lucky Strike Mine is still producing.
  The Lucky Strike Thundereggs have poorly silicified porphyic rhyolite shells that almost always contain agates in them. The agates are mostly featureless and horizontally banded. It's common to see mossy inclusions in them and few are found with plumes. The agates sometimes come in yellow, black, blue and red colors.

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Lucky Strike Mine	Valley View Mine

Rough Appearance: Both mines produces yellow speckled greenish gray "balls".
The thundereggs with biconoid cores are more likely to be from from Valley View mine.
Agates are said to be diverse with colorful (blue, yellow, white, red, and black) banded, white to gray, waterlines and moss agates.