Give chemical composition of glassy bead .

Explanation

**Step-by-Step Solution:**

1. **Understanding Glassy Bead Composition:**
- A glassy bead is primarily composed of sodium metaborate and boric anhydride.

2. **Chemical Formulas:**
- Sodium metaborate has the chemical formula \( \text{NaBO}_2 \).
- Boric anhydride has the chemical formula \( \text{B}_2\text{O}_3 \).
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