Green’s Dictionary of Slang

1. (US black) a woman’s eyes.

1964

L. Hairston ‘The Winds of Change’ in Clarke Harlem, USA (1971) 320: I knew she was buzzin’ me with her pearls.

2. (drugs) amyl nitrite [resemblance of amyl nitrite vials].

1969		R.R. Lingeman Drugs from A to Z (1970) 31: amys, also called pearls and snappers. Small glass vials containing amyl nitrite.
1972		B. Rodgers Queens’ Vernacular.
1981		D.E. Miller Bk of Jargon 338: pearls: Amyl nitrate.
2001		ONDCP Street Terms 16: Pearls — Amyl nitrite.

3. see pearlies n. (3)