Under the microscope, the mineral appeared amorphous, lacking the crystalline structure typical of quartz.
在显微镜下，这种矿物呈无定形状态，缺乏石英特有的晶体结构。
Which choice best defines “amorphous”?
C — Shapeless; formless.. “amorphous” means Shapeless; formless..
Which word means “Shapeless; formless.”?
B — amorphous. “amorphous” means Shapeless; formless..
amorphous — Shapeless; formless.. In Chinese: 无定形的；无组织的.
amorphous is pronounced //əˈmɔːrfəs//.
Under the microscope, the mineral appeared amorphous, lacking the crystalline structure typical of quartz. (在显微镜下，这种矿物呈无定形状态，缺乏石英特有的晶体结构。)
shapeless, formless, vague — all close in meaning to amorphous (Shapeless; formless.).
shaped, defined — each the opposite of amorphous (Shapeless; formless.).
Yes. amorphous is on the SAT Prep Difficult list — the higher-register words that decide the hard questions. The Digital SAT does not test vocabulary in isolation; words like this one are tested through Words in Context questions, where you choose the word that completes a passage most logically and precisely.
a-(无) + morph(形) → 无形状 → 无定形。