What Are Amorphous Crystals?

Amorphous crystals typically occur in the urine samples of health care patients 2. Several types of amorphous crystals exist, each composed of different elements and forming in specific urine conditions. The appearance and acidity of the urine sample in question can point to specific types of amorphous crystals. However, occasionally amorphous crystals are misidentified as bacteria. Crystals are found in healthy patients' urine, but they may indicate liver impairment or live disease.

Microscopic Appearance

When viewed under a microscope, amorphous crystals appear as collections of tiny grains with no defining shape or features. Some crystals, such as calcium oxyalate, appear as amorphous crystals until viewed at a higher magnification.

Amorphous Urates

Amorphous urates are crystals that form in acidic urine. These crystals are composed of the elements sodium, potassium, magnesium and calcium. They appear yellow or yellow-brown.

Amorphous Phosphates

Amorphous phosphates are crystals that form in alkaline urine. They are typically colorless.


Amorphous crystals are occasionally misidentified as bacteria. Careful observations must be made by trained individuals to rule out amorphous crystals.