Georg Wilhelm Friedrich Hegel (1770–1831) was a German philosopher. In the posthumously edited lectures the crystal appears in a discussion of transparency. The image of the “son” belongs to the addition to § 317.
What a transparent body shows
A crystal retains a definite shape and weight while allowing light to shine through it. Two properties come together before the eye that do not appear in quite the same way in an opaque body.
The primordial crystal is the diamond of the earth, in which every eye delights, recognising it as the first-born son of light and gravity.
– Georg Wilhelm Friedrich Hegel, Vorlesungen über die Naturphilosophie, p. 280.[1]
A philosophical kinship
The image joins the two sides in a relation of kinship. It does not tell how a diamond forms. What matters is what the eye can discover in a body that has weight and yet admits light.