Assertion: mineral's shape | /r/HasProperty | embedded within the obsidian
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Source sentences:
text: The products of devitrified obsidian can produce secondary fiberous mineral crystals that can form ball like shapes called spherulites that are embedded within the obsidian, these secondary minerlas can develope into what is called snowflake obsidian as well, which makes the obsidian look as if it is decorated with snowflackes due to the snowflake shapes the secondary minerals produce.