Bricks used for construction should be of good quality.Good quality of bricks shall have following properties
1. Good compressive strength
2. Low efflorescence
3. Uniform size, shape and colour
4. Low water absorption
5. evenness of baking

Unless used for load bearing structures, following quick site test generally used to check the quality of bricks.

5 quick field tests of bricks for quality check

Visual Inspection :

Brick when broken should be homogeneous in structure, compact and free from holes, cracks,fissures, air bubbles, lumps, pebbles and stones and particles of lime etc.

Uniform size and shape :

Bricks shall be of uniform size and shape. Bricks should not have broken edges and corners. Edges should be sharp and straight.Daimention variation is limited to 3 mm for class I bricks.

Ringing sound test :

When two bricks struck together, there should be clear ringing sound.

Drop test for strength check :

A brick should not break when dropped flat on hard ground from a height of about one meter.

Scratch test:

A good burned brick has its surface so hard that the fingernail cannot scratch it.

Content retrieved from: http://www.probcguide.com/civil-works/field-tests-of-bricks/.