Because it is inexpensive, calcium acetate(62-54-4) was once a common starting material for the synthesis of acetone before the development of the cumene process.
Calcium Acetate(62-54-4) can be prepared by soaking eggshells in vinegar. Since both reagants would have been available pre-historically, the chemical would have been observable as crystals then.

Reported in EPA TSCA Inventory.

The Calcium acetate is an organic compound with the formula C₄H₆CaO₄. The IUPAC name of this chemical is calcium diacetate. With the CAS registry number 62-54-4, it is also named as Diacétate de calcium . The product's classification codes are Chelating Agents; Mutation Data; Pharmaceutic Aid [buffering agent]. Besides, it is a white crystals or powder, which should be stored in a closed and dry place. It is mainly used in candy products as a food additive.

Physical properties about Calcium acetate are: (1)ACD/LogP: -0.29; (2)ACD/LogD (pH 5.5): -1.07; (3)ACD/LogD (pH 7.4): -2.86; (4)ACD/BCF (pH 5.5): 1; (5)ACD/BCF (pH 7.4): 1; (6)ACD/KOC (pH 5.5): 2.73; (7)ACD/KOC (pH 7.4): 1; (8)#H bond acceptors: 2; (9)#H bond donors: 1; (10)Polar Surface Area: 37.3 Å²; (11)Flash Point: 40 °C; (12)Enthalpy of Vaporization: 23.7 kJ/mol; (13)Boiling Point: 117.1 °C at 760 mmHg; (14)Vapour Pressure: 13.9 mmHg at 25°C.

Uses of Calcium acetate: it was formerly used to manufacture acetone by thermal decomposition:
Ca(OCOCH₃)₂ → (CH₃)₂C=O + CaO + CO₂

Preparation: this chemical can be prepared by the reaction of calcium carbonate or calcium hydroxide with acetic acid.
Ca(OH)₂ + CH₃CO₂H → Ca(OCOCH₃)₂ + 2H₂O

When you are using this chemical, please be cautious about it as the following:
This chemical is irritating to eyes, respiratory system and skin. When you are using it, wear suitable protective clothing. In case of contact with eyes, rinse immediately with plenty of water and seek medical advice.

You can still convert the following datas into molecular structure:
(1)SMILES: [Ca+2].[O-]C(=O)C.[O-]C(=O)C
(2)InChI: InChI=1/2C2H4O2.Ca/c2*1-2(3)4;/h2*1H3,(H,3,4);/q;;+2/p-2
(3)InChIKey: VSGNNIFQASZAOI-NUQVWONBAW
(4)Std. InChI: InChI=1S/2C2H4O2.Ca/c2*1-2(3)4;/h2*1H3,(H,3,4);/q;;+2/p-2
(5)Std. InChIKey: VSGNNIFQASZAOI-UHFFFAOYSA-L

The toxicity data is as follows:

Organism	Test Type	Route	Reported Dose (Normalized Dose)	Effect	Source
mouse	LD50	intraperitoneal	75mg/kg (75mg/kg)		Acta Biologica et Medica Germanica. Vol. 6, Pg. 447, 1961.
mouse	LD50	intravenous	203mg/kg (203mg/kg)		Journal of Laboratory and Clinical Medicine. Vol. 29, Pg. 809, 1944.
rat	LDLo	intravenous	147mg/kg (147mg/kg)		Journal of Pharmacology and Experimental Therapeutics. Vol. 71, Pg. 1, 1941.