A (sapphire crystal) can be synthetic.Logical formLearned from18 sentences. A crystal can be broken.Logical formLearned from18 sentences. A crystal can be synthetic.Logical formLearned from18 sentences. A center may pertain-to a crystal.Logical formLearned from18 sentences. (Oil drillers) may encounter pockets of (methane crystals).Logical formLearned from18 sentences. Pockets can be constituted-of-or-filled-with (methane crystals).Logical formLearned from18 sentences. A crystal can be czech.Logical formLearned from18 sentences. A (crystal globe) can be coveted.Logical formLearned from18 sentences. Crystals can be pale.Logical formLearned from17 sentences. Properties may pertain-to crystals.Logical formLearned from17 sentences. A female may sing about (crystal meth).Logical formLearned from17 sentences. Some crystals may surround bodies.Logical formLearned from17 sentences. A crystal can be brighter.Logical formLearned from17 sentences. Crystals can be in an urine.Logical formLearned from17 sentences. A (crystal chandelier) can be genuine.Logical formLearned from17 sentences.