Flame Tests

This table of flame coloration is modified from the book "Determinative Mineralogy and Blowpipe Analysis" by Brush & Penfield, 1906. The colors are best observed by heating the sample on a loop of platinum wire moistened with HCl. The spectra are calculated to represent the emission from a flame and are based on the work of John Talbot. Additional data for each element were obtained from the National Institute of Standards and Technology.

Color	Shade or Tone	Element	Remarks
Red	Crimson	Li	The lithium minerals, which are either silicates or phosphates, do not become alkaline after ignition. Compare Strontium.
Flame Spectrum

Red	Crimson	Sr	Carbonates and sulfates show the strontium reaction, and become alkaline after ignition. Silicates and phosphates do not give the strontium flame.
Flame Spectrum

Red	Yellowish to orange	Ca	Only a few minerals give this calcium color decisively when heated alone. Often, however, the color shows distinctly after moistening the assay with hydrochloric acid.
Flame Spectrum

Yellow	Intense	Na	This test for sodium is so delicate that great care must be exercised in using it. Glass blowers Didymium Safety Glasses may be used to block out this emission to observe the less intense colors.
Flame Spectrum

Green	Yellowish	Ba	Carbonates and sulfates show the reaction, and become alkaline after ignition. Silicates and phosphates do not give the barium flame.
Flame Spectrum

Green	Yellowish	Mo	If the molybdenum is in the form of the oxide or the sulfide.
Flame Spectrum

Green	Bright, somewhat yellowish	B	Boron compounds rarely show an alkaline reaction after ignition. Green color is due to the blue and orange in the spectrum.
Flame Spectrum

Green	Pure	Tl	Not often observed due to the rarity of thallium-bearing minerals.
Flame Spectrum

Green	Pale bluish	P	The phosphorus color is not very decisive, but often aids in the identification of a phosphate.
Flame Spectrum

Green	Bluish	Zn	Zinc appears as bright streaks in the flame.
Flame Spectrum

Green	Pale	Te	Tellurium is not very decisive.
Flame Spectrum

Green	Pale	Sb	Antimony is not very decisive.
Flame Spectrum

Green	Pale	Pb	Lead is not very decisive.
Flame Spectrum

Blue	Azure	CuCl₂	The copper flame color is dependent on the presence of halide (I, F, Br, or Cl). The color can be used to detect halides by using copper oxide moistened with test solution. The outer darts of the flame are tinged with emerald-green.
Flame Spectrum

Blue	Azure	Se	The selenium color is accompanied by the characteristic odor of rotting radishes.
Flame Spectrum

Blue		In	The element Indium is named for the prominent blue lines in its spectrum.
Flame Spectrum

Blue		As	The arsenic color is accompanied by the characteristic odor of garlic.
Flame Spectrum

Violet	Pale	K	The potassium color is often masked by the more prominent yellow from sodium.
Flame Spectrum

Violet	Pale	Rb	The rubidium color is often masked by the more prominent yellow from sodium.
Flame Spectrum

Violet	Pale	Cs	The cesium color is often masked by the more prominent yellow from sodium. The first element found using a spectroscope.
Flame Spectrum

Flame Tests

Flame Coloration by Element

Table of Flame Colorations and Emission Spectra