Green’s Dictionary of Slang

chalk n.3

[the colour]

1. (US) milk or cream.

[US]C.G. Givens ‘Chatter of Guns’ in Sat. Eve. Post 13 Apr.; list extracted in AS VI:2 (1930) 132: chalk, n. Milk.
[US]Weseen Dict. Amer. Sl.
[UK]J. Lees-Milne Ancestral Voices diary 22 June (1975) 81: At luncheon the waiter asked, ‘Will you have cream with your gooseberries, m’m?’ ‘es, rather,'’said Nancy. ‘Delicious chalk’.
[US]Monteleone Criminal Sl. (rev. edn).
[US]Wentworth & Flexner DAS.

2. (US black) a white person; thus chalkette, a white woman.

[US]S. Lewis Kingsblood Royal (2001) 136: Most of us sables would rather marry a gal like Sophie than a chalkette.
[US]C. Himes Blind Man with a Pistol (1971) 122: You sniffing at the wrong tuft, Slick, baby [...] She like chalk.
[US]E. Folb Runnin’ Down Some Lines 60: The single most descriptive attribute young blacks focus on in their labeling of whites is color – or the lack of it – such as [...] chalk, lily, pale face.

3. US drug uses.

(a) methamphetamine, Benzedrine or Methedrine.

[US]R.R. Lingeman Drugs from A to Z (1970) 59: chalk [...] amphetamine tablets.
[US]R. Sabbag Snowblind (1978) 240: The most popular word is ups. Brain ticklers, browns, cartwheels, chalk [...] are words of the sixties and are out of use now.
[US]E. Folb Runnin’ Down Some Lines 169: Benzedrine – variously called white, benny, bean, chalk, or wake-up.
[US]D.E. Miller Bk of Jargon 337: chalk: Amphetamines.
[US]ONDCP Street Terms 5: Chalk — [...] amphetamine [...] methamphetamine.

(b) cocaine.

[US]Illinois Legislative Investigating Committee Drug Crisis in Spears (1986).

(c) Methadone [may be an error, confusing the abbr. ‘meth’ used for sense 3a].

[US] S.N. Pradhan Drug Abuse.

(d) crack cocaine.

[US]ONDCP Street Terms 5: Chalk — Crack Cocaine.

In phrases

chalk and cheese (n.)

(N.Z. prison) a pair of very close friends.

[NZ]D. Looser Boobslang [U. Canterbury D.Phil. thesis] 40/1: chalk and cheese n. two inmates who are very close friends and spend much of their time together.