Table 1 – Some physical features for investigates chicken stomach stones (gastroliths).

	Colorless	Colorless	Green	Green	Amber	Amber	Amber
Stones	1	2	1	2	1	2	3
Length (mm)	10	8	7,5	7	nd	8	5
Width (mm)	4	6	6	4	nd	2,5	3
Density (g/cm^3)	2,4324	nd	2,4811	nd	2,4639	nd	nd
Hardness	5,5 - 6	5,5 - 6	5,5 - 6	5,5 - 6	5,5 - 6	5,5 - 6	5,5 - 6
Luster	Vitreous	Vitreous	Vitreous	Vitreous	Vitreous	Vitreous	Vitreous
Diafanity	Transparent	Transparent	Transparent	Transparent	Transparent	Transparent	Transparent
Surface	Matte	Matte	Matte	Matte	Matte	Matte	Matte
Rounding	4-5	4-5	4-5	4-5	4-5	4-5	4-5
Sphericity	Low	Low	Low	Low	Low	Low	Low

Rounding: 4: sub rounded; 5: rounded. Nd: not determined.