Rapid Identification of Nine Easily Confused Mineral Traditional Chinese Medicines Using Raman Spectroscopy Based on Support Vector Machine

Table 1

Characteristics of nine mineral TCMs.

Mineral TCMs	Shape	Color	Diaphaneity	Tenacity	Lustre	Odor	Taste
Borax [4]	Irregular, massive	Colorless to white	Transparent to translucent	Brittle	Vitreous	Odorless	Slightly salty, slightly sweet
Gypsum fibrosum [1]	Fibrous masses, tabular, or irregularly massive	White, gray white, or pale yellow	Translucent	Flexible	Silky	Odorless	Bland
Natrii sulfas exsiccatus [1]	Powder	White	—	—	—	Odorless	Salty
Natrii sulfas [1]	Prismatic, oblong, irregularly shaped, or granular	Colorless or off-white	Transparent or translucent	Brittle	Vitreous	Odorless	Salty
Alumen [1]	Irregular massive or granular	Colorless or yellowish-white	Transparent or translucent	Brittle	Vitreous	Odorless	Sour, slightly sweet, very astringent
Sal ammoniac [5]	Naturally occurring sal ammoniac are irregular platy crystals, and the synthetic one is cuboid	Colorless, white, pale gray, yellowish-white, or brown	Transparent or translucent	Brittle	Vitreous	Sulfury	Salty, bitter
Quartz [4]	6-sided prism or coarse granular aggregation with sharp edges	White or gray white	Translucent to opaque	Hard	Greasy	Odorless	Bland
Calcite [5]	Rhombohedral flat masses, rhombohedral prism	White, pale yellow, or pale red	Transparent to translucent	Brittle	Vitreous	Odorless	Tasteless
Yellow croaker otolith [4]	Oblong, ovoid, trigonous. One end is rounded, and the other is pointed.	White	Opaque	Brittle	Porcellaneous	Odorless	Bland, slightly astringent